Answer in brief
CVE-2026-77205 records a Low severity (CVSS 3.7) vulnerability in Denial of Service via sending bogus X.509 certificates. The current sources do not mark it as known exploited. The current feed maps The Libreswan Project/libreswan (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 3.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps The Libreswan Project/libreswan (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| The Libreswan Project/libreswangeneric | >=5.3 <=5.3.2 | Not reported |
Published upstream
Oct 13, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 13, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 13, 2026
Libreswan in FIPS mode has a vulnerability where badly formed received certificates are rejected, but not deleted from the NSS cache. As a result, any real certificates with the same serial number are rejected as well. This can be abused to lock out legitimate peers from connecting. The add_decoded_cert() function missed a call to CERT_DestroyCertificate() due to an incorrect fix for CVE-2026-14957. Sending bogus certificates with new serial numbers could prevent the real certificates with those serial numbers from connecting until the service has restarted.
Quoted source text, attributed separately from HOL analysis.