How to Identify Compromised eMudhra Certificates With Qualys (CVE-2026-111943)

Madhuri C

Last updated on: October 27, 2026


Executive Summary

A critical certificate authority incident disclosed on October 17, 2026, impacts eight eMudhra intermediate CA certificates. A flaw in the key generation process could allow attackers to recover private keys and issue fraudulent TLS or code-signing certificates. The affected intermediates have been revoked and blocked by major platform vendors, including Chrome, Mozilla, Apple, and Microsoft. The issue is tracked as CVE-2026-111943.


The eMudhra Certificate Authority Compromise

On October 17, 2026, a researcher reported recovering the private keys for eight eMudhra intermediate CA certificates after discovering that the underlying cryptographic keys contained only a fraction of the expected entropy. Browser and OS vendors have since blocked the certificates, and eMudhra has revoked them. Security teams now face an immediate question: Where do certificates issued by the compromised eMudhra intermediates exist within my environment?

Qualys VMDR and Qualys Certificate View already collect the data needed to answer that. This post explains how to use them, with QQL queries you can run today.

What is eMudhra?

eMudhra, a digital trust and cybersecurity provider, offers solutions spanning Public Key Infrastructure (PKI), digital certificates, identity management, and secure digital transactions. Recent security concerns involving eight of its intermediate Certificate Authority (CA) certificates highlight the importance of strong cryptographic key generation, rigorous validation, and continuous oversight of digital trust infrastructure. The incident reinforces a critical security lesson: trust in digital certificates depends not just on the technology, but on the operational controls protecting the keys behind them.

What Happened

A flaw in eMudhra’s key generation process produced a second set of weak P-384 keys during a wrap/unwrap step, and those weak keys were mistakenly used for eight intermediate CA certificates. This flaw reduced the effective entropy of the affected P-384 keys to an estimated 3 to 8 bits, making private-key recovery trivial to compute.

The weak keys came from a key generation ceremony held on April 30, 2025, for 24 subordinate CAs. Anyone holding the private key of one of these intermediates could issue a certificate that impersonates any website or service, subject to each client’s validation controls. Some key points about the incident:

  • Six of the eight intermediates are TLS CAs; two are code-signing CAs.
  • Browsers: Chrome, Mozilla, and Apple have blocked the TLS certificates, and Microsoft has blocked the two code-signing certificates.
  • Root distrust: Google removed the emSign ECC Root CA – G3 from the Chrome Root Store, and Mozilla removed trust in the root that signed the intermediates.
  • eMudhra: has revoked the eight certificates and stopped issuing new certificates under its G3 root. It states that its root CA private keys and other intermediate CAs are not affected, and that the issue is limited to its global website-security business, not Indian DSC and eSign services.
  • Exploitation: eMudhra says only one of the affected intermediates was used in production, and none of them issued certificates to websites or end users.

Who is at Most Risk?

Organizations should prioritize investigation if they:

  • Operate internet-facing websites, APIs, VPNs, or other TLS-enabled services.
  • Use publicly trusted certificates issued through eMudhra or emSign trust hierarchies.
  • Distribute signed software that relies on publicly trusted code-signing certificates.
  • Develop or run applications built on the Go programming language.
  • Maintain legacy systems, unmanaged endpoints, or custom trust stores that may not receive certificate distrust updates automatically.

The Eight Affected Intermediate Certificates

The table below lists the certificates identified. The SHA-256 fingerprint and serial number are the most reliable identifiers when you search your inventory.

Certificate (organization)TypeCCADB IDSerial numberSHA-256 fingerprint
EM EV TLS CA – G3B (eMudhra BV)TLSA012304c7c41efe92d825f05eae841a4a82c1E7568FE6E12331F4FD7DE61DA4C7559D0F8EB192A218D4741A3BA75184333838
EM OV TLS CA – G3B (eMudhra BV)TLSA0123086cada367fb1c100088120ea202d56898B896625C0C230ADEEC3EB2CF6AAD5001ECF9156A68644E82374CE5833BC25B
EM DV TLS CA – G3B (eMudhra BV)TLSA012302a4aee678f23362b4c0e460b772f21442C4ACCD12C4F59597925E1A08A7A90102608543809308D50EC427E118BA1493
EM EV TLS CA – G3C (eMudhra Inc)TLSA0122968009928a64107601af05fa2f19f109432EC25F0D28DE9006D97BF752F17BBB2CD41F669933FCB072D9A1148D0261F3
EM OV TLS CA – G3C (eMudhra Inc)TLSA012300296926c227a3a1526392b19482a504CB6E15165AC802E9B3F993F16C25D41F4E81C21EBDE71AE1B012AC00BF9C7C3F
EM DV TLS CA – G3C (eMudhra Inc)TLSA012294588b2e3c2bb8cda13e1a12092543210164D7CEAE5BB909C272AF151FF44B1177AE9B47D9424B94F1D9558C30934D19
EM OV CS CA – G3B (eMudhra BV)Code signingA0123067818933f8f85b4619a2b35fba83d0a9E39DE2881273ACC225A149C72BA3E0F51424963669AB633EE1DC7DF5DB067B4
EM OV CS CA – G3C (eMudhra Inc)Code signingA012298544b7f922c31ae220a4a922916f6e64B2460A466F95FD40113BCDCCA2CEB29B3B093921DE45474DA7DF48874C630B1

How Can Qualys VMDR and Certificate View Help Identify eMudhra Certificates?

Use Certificate View, included with VMDR, to identify certificates issued by affected eMudhra authorities and use VMDR with Cloud Agent to identify hosts running vulnerable Go installations or software requiring vendor-issued updates.

Step 1: Make Sure Coverage Is Complete

  • Entitle Certificate View on your VMDR scan ranges. Confirm that the IP ranges you scan with VMDR are enabled in Certificate View.
  • Add external domains. For sites hosted by web or app providers, add the FQDNs or IP addresses in Certificate View. It runs a lightweight scan across standard ports to detect TLS services and analyze their certificates.
  • Use Cloud Agent where scans cannot reach. Agents report software and certificate data from endpoints, servers, and remote workers that network scans miss.

Step 2: Pinpoint the Eight Compromised Intermediates

To confirm whether any of the eight compromised intermediates appear in a chain, search for their SHA-256 fingerprints, serial numbers, or issuer names in Certificate View > Certificates.

Reference QQL Queries

By Issuer:

certificate:(issuer.name:[`EM EV TLS CA – G3B`, `EM OV TLS CA – G3B`, `EM DV TLS CA – G3B`, `EM EV TLS CA – G3C`, `EM OV TLS CA – G3C`, `EM DV TLS CA – G3C`, `EM OV CS CA – G3B`, `EM OV CS CA – G3C`])

By Serial Number:

certificate:(serialNumber:`c7c41efe92d825f05eae841a4a82c1` or serialNumber:`6cada367fb1c100088120ea202d568` or serialNumber:`a4aee678f23362b4c0e460b772f214` or serialNumber:`8009928a64107601af05fa2f19f109` or serialNumber:`296926c227a3a1526392b19482a504` or serialNumber:`588b2e3c2bb8cda13e1a1209254321` or serialNumber:`7818933f8f85b4619a2b35fba83d0a` or serialNumber:`544b7f922c31ae220a4a922916f6e6`)

The Information tab shows the fingerprints, serial number, and first and last found dates so that you can compare them with the SHA-256 values in the table.

Step 3: Find Software That Still Trusts the Affected Certificates

Certificates presented by your servers are only half of the exposure. Applications running older Go runtimes may continue to trust certificate chains containing the compromised intermediates. VMDR/Cloud Agent can help you find them.

Find Go toolchains to update

Go 1.27.3 and 1.26.10 block certificate chains that contain any of the eight compromised keys (CVE-2026-111943). Qualys has released QID 5019897 for SwCA scanning to detect affected Go versions. Before you scan, confirm your agents have the latest signatures that include this QID, so the new scan picks it up. Then open the Vulnerabilities tab and use the query below to list the impacted assets:

vulnerabilities.vulnerability.qid:5019897

Find Additional Vendor-Specific Updates

Qualys has also released QIDs to detect Go vulnerabilities associated with other vendor operating systems.

QIDTitleCategory
6056530Red Hat Update for go-toolset:rhel8 security (RHSA-2026:87245)RedHat
766002SUSE Enterprise Linux Security Update for go1.26-Open Secure Sockets Layer (OpenSSL) (SUSE-SU-2026:4867-1)SUSE
766008SUSE Enterprise Linux Security Update for go1.26-Open Secure Sockets Layer (OpenSSL) (SUSE-SU-2026:4866-1)SUSE
6056575Red Hat Update for grafana-pcp (RHSA-2026:88394)RedHat
6056553Red Hat Update for grafana (RHSA-2026:88340)RedHat
6056565Red Hat Update for grafana (RHSA-2026:88339)RedHat
6056570Red Hat Update for grafana-pcp (RHSA-2026:88395)RedHat
290616Fedora Security Update for rust (FEDORA-2026-1ffbf97eba)Fedora
6601071Oracle Enterprise Linux Security Update for buildah (ELSA-2026-88262)OEL
364253Amazon Linux Security Advisory for docker : ALAS2ECS-2026-150Amazon Linux
364251Amazon Linux Security Advisory for runc : ALAS2ECS-2026-151Amazon Linux
364332Amazon Linux Security Advisory for buildah : ALAS2023-2026-3326Amazon Linux
364213Amazon Linux Security Advisory for docker : ALAS2NITRO-ENCLAVES-2026-129Amazon Linux
6601042Oracle Enterprise Linux Security Update for grafana-pcp (ELSA-2026-88189)OEL
364333Amazon Linux Security Advisory for skopeo : ALAS2023-2026-3325Amazon Linux
6601077Oracle Enterprise Linux Security Update for golang-github-openprinting-ipp-usb (ELSA-2026-88280)OEL
6601079Oracle Enterprise Linux Security Update for ca-certificates (ELSA-2026-500496)OEL
6601080Oracle Enterprise Linux Security Update for grafana (ELSA-2026-88188)OEL
6056541Red Hat Update for grafana-pcp (RHSA-2026:88354)RedHat
364268Amazon Linux Security Advisory for git-lfs : ALAS2023-2026-3322Amazon Linux
6056537Red Hat Update for grafana-pcp (RHSA-2026:88317)RedHat
6056542Red Hat Update for grafana (RHSA-2026:87732)RedHat
964554Rocky Linux Security Update for grafana (RLSA-2026:88188)Rocky Linux
6601047Oracle Enterprise Linux Security Update for grafana-pcp (ELSA-2026-88316)OEL
6601053Oracle Enterprise Linux Security Update for go-toolset:ol8 (ELSA-2026-86203)OEL
6684042CloudLinux 9 Security Update for grafana-pcp (CLSA-2026:88354)CloudLinux
945727AlmaLinux Security Update for grafana (ALSA-2026:88188)AlmaLinux
945728AlmaLinux Security Update for grafana-pcp (ALSA-2026:88189)AlmaLinux
964555Rocky Linux Security Update for grafana-pcp (RLSA-2026:88316)Rocky Linux
945745AlmaLinux Security Update for grafana-pcp (ALSA-2026:88316)AlmaLinux
945746AlmaLinux Security Update for podman (ALSA-2026:88336)AlmaLinux
364203Amazon Linux Security Advisory for cri-tools : ALAS2-2026-4042Amazon Linux
766006SUSE Enterprise Linux Security Update for go1.27 (SUSE-SU-2026:4863-1)SUSE
766003SUSE Enterprise Linux Security Update for go1.26 (SUSE-SU-2026:4864-1)SUSE
364299Amazon Linux Security Advisory for docker : ALAS2023-2026-3324Amazon Linux
964557Rocky Linux Security Update for podman (RLSA-2026:88336)Rocky Linux
964558Rocky Linux Security Update for grafana-pcp (RLSA-2026:88354)Rocky Linux
964566Rocky Linux Security Update for grafana-pcp (RLSA-2026:88189)Rocky Linux
964567Rocky Linux Security Update for buildah (RLSA-2026:88262)Rocky Linux
6601033Oracle Enterprise Linux Security Update for golang (ELSA-2026-86093)OEL
6056574Red Hat Update for grafana (RHSA-2026:88188)RedHat
6056551Red Hat Update for grafana-pcp (RHSA-2026:88189)RedHat
6056552Red Hat Update for golang-github-openprinting-ipp-usb (RHSA-2026:88280)RedHat
6056573Red Hat Update for grafana (RHSA-2026:88397)RedHat
945742AlmaLinux Security Update for grafana-pcp (ALSA-2026:88354)AlmaLinux
6601081Oracle Enterprise Linux Security Update for grafana-pcp (ELSA-2026-88354)OEL
6056540Red Hat Update for grafana-pcp (RHSA-2026:88316)RedHat
6056545Red Hat Update for grafana (RHSA-2026:88332)RedHat
6056546Red Hat Update for grafana (RHSA-2026:88396)RedHat
364270Amazon Linux Security Advisory for runc : ALAS2023-2026-3323Amazon Linux
364229Amazon Linux Security Advisory for runc : ALAS2DOCKER-2026-154Amazon Linux
364220Amazon Linux Security Advisory for docker : ALAS2DOCKER-2026-155Amazon Linux
364219Amazon Linux Security Advisory for runc : ALAS2NITRO-ENCLAVES-2026-128Amazon Linux
945749AlmaLinux Security Update for golang-github-openprinting-ipp-usb (ALSA-2026:88280)AlmaLinux
6666650Alpaquita Linux Security Update for go (CVE-2026-111943)Bellsoft Alpaquita Linux
6601073Oracle Enterprise Linux Security Update for podman (ELSA-2026-88336)OEL
6056556Red Hat Update for buildah (RHSA-2026:88262)RedHat
6056562Red Hat Update for podman (RHSA-2026:88336)RedHat
364206Amazon Linux Security Advisory for golang : ALAS2-2026-4043Amazon Linux
964570Rocky Linux Security Update for golang-github-openprinting-ipp-usb (RLSA-2026:88280)Rocky Linux
945732AlmaLinux Security Update for buildah (ALSA-2026:88262)AlmaLinux
364264Amazon Linux Security Advisory for golang : ALAS2023-2026-3327Amazon Linux
6056535Red Hat Update for grafana-pcp (RHSA-2026:87911)RedHat
6056520Red Hat Update for go-toolset:rhel8 security (RHSA-2026:87246)RedHat
6684005CloudLinux 8 Security Update for go-toolset:rhel8 (CLSA-2026:86203)CloudLinux
6601039Oracle Enterprise Linux Security Update for golang (ELSA-2026-86196)OEL
6684017CloudLinux 9 Security Update for golang (CLSA-2026:86196)CloudLinux
290608Fedora Security Update for rust (FEDORA-2026-8eeffa4c43)Fedora
711201Gentoo Linux ca-certificates Compromised Intermediate Certificate Authority Vulnerability (GLSA 202610-01)GentooOS
945683AlmaLinux Security Update for go-toolset:rhel8 (ALSA-2026:86203)AlmaLinux
945690AlmaLinux Security Update for golang (ALSA-2026:86196)AlmaLinux
945699AlmaLinux Security Update for golang (ALSA-2026:86093)AlmaLinux
964523Rocky Linux Security Update for golang (RLSA-2026:86093)Rocky Linux
6056489Red Hat Update for golang security (RHSA-2026:86196)RedHat
5019897Go (Go) Security Update for stdlib (GO-2026-6809)SCA
6056475Red Hat Update for go-toolset:rhel8 security (RHSA-2026:86203)RedHat
6056480Red Hat Update for golang security (RHSA-2026:86093)RedHat
6056514Red Hat Update for golang security (RHSA-2026:87041)RedHat
6056513Red Hat Update for grafana-pcp (RHSA-2026:86972)RedHat
6056506Red Hat Update for golang security (RHSA-2026:87042)RedHat
6056505Red Hat Update for grafana-pcp (RHSA-2026:86973)RedHat
6056501Red Hat Update for golang security (RHSA-2026:87043)RedHat
964525Rocky Linux Security Update for golang (RLSA-2026:86196)Rocky Linux
6056500Red Hat Update for golang security (RHSA-2026:87040)RedHat
6601015Oracle Enterprise Linux Security Update for ca-certificates (ELSA-2026-500451)OEL
6601013Oracle Enterprise Linux Security Update for ca-certificates (ELSA-2026-500449)OEL
6601022Oracle Enterprise Linux Security Update for ca-certificates (ELSA-2026-500450)OEL

vulnerabilities.vulnerability.qid:[364203,364206,364213,364219,364220,364229,364251,364253,364264,364268,364270,364299,364332,364333,45804,290608,290616,711201,766002,766003,766006,766008,945683,945690,945699,945727,945728,945732,945742,945745,945746,945749,964523,964525,964554,964555,964557,964558,964566,964567,964570,5019897,6056475,6056480,6056489,6056500,6056501,6056505,6056506,6056513,6056514,6056520,6056530,6056535,6056537,6056540,6056541,6056542,6056545,6056546,6056551,6056552,6056553,6056556,6056562,6056565,6056570,6056573,6056574,6056575,6601013,6601015,6601022,6601033,6601039,6601042,6601047,6601053,6601071,6601073,6601077,6601079,6601080,6601081,6666650,6684005,6684017,6684042]

Enumerate Affected eMudhra Certificate Chains

In addition to software detection, Qualys is releasing QID 48395: eMudhra Intermediate CA Certificates Enumeration. This Information Gathered (IG) QID helps identify systems presenting or using certificate chains that contain the affected eMudhra intermediate CA certificates. Once available in your subscription, you can query for assets using:

vulnerabilities.vulnerability.qid:48395

Optional Check: Find eMudhra-Issued Certificates with QQL Queries in Certificate View

Open Certificate View > Certificates, paste the query below into the search bar, and run it. It matches any certificate whose issuer organization is one of the eMudhra entities in the affected list.

certificate:(issuer.organization:`eMudhra BV` or issuer.organization:`eMudhra Inc`)

The results list each certificate with its issuer, validity dates, and the assets and ports where it was found. Use the left-pane filters, such as Expiring Certificates and Certificate Authority, to sort the results by urgency.

The two organizations that matter most for this incident are eMudhra BV and eMudhra Inc, because they are the organizations named on the eight compromised intermediates (the G3B and G3C certificates).

Tip: save the query as a dashboard widget in Certificate View, so any new eMudhra-issued certificate that appears is flagged automatically.

Note: QQL query tokens are case-sensitive. If a query returns a syntax error, check the search token list in the Certificate View help and adjust the token name.

Response and Remediation

  1. Replace affected certificates first. Any leaf certificate whose chain includes one of the eight intermediates should be reissued by another trusted CA and redeployed with the correct chain.
  2. Updates. Apply operating system security updates and upgrade Go runtimes to supported releases that reject certificate chains containing the compromised intermediates.
  3. Confirm revocation behavior. eMudhra has revoked the eight certificates, but clients that do not check revocation can still accept them. Validate that certificate revocation checks are functioning correctly and that revocation lists are up to date.
  4. Monitor continuously. Monitor dashboards after each scan cycle until results are clean.

Conclusion

The eMudhra incident is a reminder that trust depends on both the certificates you present and the authorities you trust. Certificate View gives you the issuer search and dashboards to find eMudhra-issued certificates, and VMDR and Cloud Agent inventory show which hosts and applications still need vendor updates. Qualys enables organizations to quickly discover affected assets, validate exposure, and confidently prioritize response efforts.


Start your risk-free trial of VMDR. If you are not yet using VMDR to measure, communicate, and eliminate risk, start a 30-day trial and use Certificate View to get a full view of your certificates.


Frequently asked questions:

QuestionQualys capabilityWhat you get
Which certificates in my environment were issued by eMudhra entities?Certificate View, QQL query on issuer organizationA list of certificates with host, port, expiry and issuer details
Are any of the eight compromised intermediates in a certificate chain?Certificate View, certificate path and fingerprint or serial searchExact match to the CCADB-listed intermediates
Which hosts are affected?VMDR asset inventory, tags and dashboardsAffected assets grouped by business unit or tag
Which hosts and applications still use outdated trust stores or vulnerable Go runtimes?VMDR / Cloud Agent software inventoryHosts with outdated ca-certificates packages or Go versions

References

Contributors

  • Russ Sanderlin, Director, Subject Matter Expert, VMDR, Qualys
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