Exim4: Exim before 4.100.1, when certain non-default TLS settings are used with GnuTLS, has a use-after-free. (CVE-2026-94055)
Exim versions before 4.100.1 that use certain non-default TLS settings with GnuTLS contain a use-after-free vulnerability. This flaw can cause a denial of service but does not impact confidentiality or integrity. The vulnerability has a medium severity rating with a CVSS score of 3.7. Several specific Ubuntu package versions of Exim4 are affected. No known exploits are reported in the wild. A fixed version 4.100.1 is available.
AI Analysis
Technical Summary
Exim before version 4.100.1, when configured with certain non-default TLS settings using GnuTLS, suffers from a use-after-free vulnerability. This memory management flaw can lead to application crashes or denial of service conditions. The issue is limited to specific configurations and does not affect confidentiality or integrity of data. The vulnerability has been assigned CVE-2026-94055 and carries a CVSS v3.1 base score of 3.7, indicating medium severity.
Potential Impact
The vulnerability can cause denial of service by triggering a use-after-free condition in Exim when using certain non-default TLS settings with GnuTLS. There is no impact on confidentiality or integrity. No known active exploitation has been reported.
Mitigation Recommendations
Upgrade to Exim version 4.100.1 or later, which contains the fix for this use-after-free vulnerability. If upgrading is not immediately possible, avoid using the affected non-default TLS settings with GnuTLS until patched.
Exim4: Exim before 4.100.1, when certain non-default TLS settings are used with GnuTLS, has a use-after-free. (CVE-2026-94055)
Description
Exim versions before 4.100.1 that use certain non-default TLS settings with GnuTLS contain a use-after-free vulnerability. This flaw can cause a denial of service but does not impact confidentiality or integrity. The vulnerability has a medium severity rating with a CVSS score of 3.7. Several specific Ubuntu package versions of Exim4 are affected. No known exploits are reported in the wild. A fixed version 4.100.1 is available.
CVSS v3.1
Score 3.7low
Affected software
pkg:deb/ubuntu/exim4?arch=source&distro=resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Exim before version 4.100.1, when configured with certain non-default TLS settings using GnuTLS, suffers from a use-after-free vulnerability. This memory management flaw can lead to application crashes or denial of service conditions. The issue is limited to specific configurations and does not affect confidentiality or integrity of data. The vulnerability has been assigned CVE-2026-94055 and carries a CVSS v3.1 base score of 3.7, indicating medium severity.
Potential Impact
The vulnerability can cause denial of service by triggering a use-after-free condition in Exim when using certain non-default TLS settings with GnuTLS. There is no impact on confidentiality or integrity. No known active exploitation has been reported.
Mitigation Recommendations
Upgrade to Exim version 4.100.1 or later, which contains the fix for this use-after-free vulnerability. If upgrading is not immediately possible, avoid using the affected non-default TLS settings with GnuTLS until patched.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-94055
- Osv Schema Version
- 1.7.0
- Ecosystems
- ["Ubuntu:26.04:LTS"]
- Cvss Version
- 3.1
Threat ID: 6ab4be27f7a7c54106eee994
Added to database: 09/24/2026, 06:07:35 UTC
Last enriched: 09/24/2026, 06:21:23 UTC
Last updated: 09/25/2026, 01:47:46 UTC
Views: 4
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