CVE-2026-77205: CWE-772: Missing Release of Resource after Effective Lifetime in The Libreswan Project libreswan
Description
Libreswan versions 5.3 through 5.3.2 running in FIPS mode have a vulnerability where malformed certificates are rejected but not removed from the NSS cache. This causes legitimate certificates with the same serial number to be rejected, potentially locking out legitimate peers until the service is restarted.
CVSS v3.1
Score 3.7low
Affected software
The Libreswan Project
libreswan
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Libreswan project in versions 5.3 to 5.3.2 contains a resource management flaw (CWE-772) in FIPS mode where the add_decoded_cert() function fails to call CERT_DestroyCertificate() on badly formed certificates. These certificates remain cached in NSS, causing any legitimate certificates with the same serial number to be rejected. This issue stems from an incorrect fix for CVE-2026-14957. Attackers can exploit this by sending bogus certificates with new serial numbers to prevent legitimate peers from connecting until the service restarts.
Potential Impact
The vulnerability can cause a denial of service condition by locking out legitimate peers from connecting due to cached bogus certificates with conflicting serial numbers. There is no impact on confidentiality or integrity, only availability is affected. The CVSS score is 3.7 (low severity) reflecting this limited impact.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restarting the Libreswan service clears the NSS cache and restores connectivity. Monitor vendor communications for an official fix addressing the missing CERT_DestroyCertificate() call.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- libreswan
- Date Reserved
- 2026-08-20T18:13:09.377Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6acea4022cdf04f656b3059b
Added to database: 10/13/2026, 21:34:58 UTC
Last enriched: 10/13/2026, 21:48:38 UTC
Last updated: 10/13/2026, 21:50:44 UTC
Views: 6
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