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PatchSiren cyber security CVE debrief

CVE-2026-94055 Exim CVE debrief

A use-after-free vulnerability exists in Exim before version 4.100.1 when certain non-default TLS settings are used with GnuTLS. This CVE was published on 2026-09-19T23:17:10.973Z and has not been modified since then. The vulnerability can lead to potential denial of service due to the use-after-free condition. Defenders should assess exposure and prioritize updates to version 4.100.1 or later. The CVE record and NVD entry provide limited information about the vulnerability, and further verification is required to determine the scope of affected systems and potential impact.

Vendor
Exim
Product
Unknown
CVSS
LOW 3.7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-19
Original CVE updated
2026-09-19
Advisory published
2026-09-19
Advisory updated
2026-09-19

Who should care

Defenders responsible for Exim installations should assess exposure and prioritize updates to version 4.100.1 or later. They should also review system inventory for Exim installations, monitor Exim logs for potential exploitation attempts, and verify Exim configurations. This is crucial due to the potential denial of service caused by the use-after-free vulnerability in Exim before version 4.100.1 when certain non-

Why it matters

Defenders should prioritize verifying Exim configurations and updating to version 4.100.1 or later due to a use-after-free vulnerability in Exim before version 4.100.1 when certain non-default TLS settings are used with GnuTLS.

  • Potential denial of service due to use-after-free condition
  • Requires verification of Exim configurations and updates to version 4.100.1 or later

Technical summary

The CVE-2026-94055 vulnerability exists in Exim before version 4.100.1 when certain non-default TLS settings are used with GnuTLS, leading to a use-after-free condition. This condition can result in potential denial of service. The vulnerability requires verification of Exim configurations and updates to version 4.100.1 or later. The CVE record and NVD entry provide limited information about the vulnerability.

Defensive priority

Defenders should prioritize verifying Exim configurations and updating to version 4.100.1 or later.

Recommended defensive actions

  • Verify Exim configurations and update to version 4.100.1 or later
  • Review system inventory for Exim installations
  • Monitor Exim logs for potential exploitation attempts

Evidence notes

The CVE record and NVD entry provide limited information about the vulnerability. Further verification is required to determine the scope of affected systems and potential impact.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-94055 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-94055

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-94055 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-94055

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.