Denial of Service via sending bogus X.509 certificates
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.
CVE-2026-77205
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-77205
libreswan
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://github.com/libreswan/libreswan",
"vendor": "The Libreswan Project",
"product": "libreswan",
"versions": [
{
"status": "affected",
"version": "5.3",
"versionType": "semver",
"lessThanOrEqual": "5.3.2"
},
{
"status": "unaffected",
"version": "5.3.3",
"versionType": "semver"
}
],
"packageName": "libreswan",
"collectionURL": "https://github.com/libreswan/libreswan",
"defaultStatus": "unaffected",
"programRoutines": [
{
"name": "add_decoded_cert"
}
]
}
]- Related CVEs
- CVE-2026-77205
Source reference:
/cveMetadata/cveId
Publisher severity
low
Source reference: /containers/cna/metrics
- Event
- #32661 · Revision 1
- Added to Heist Feed
- Publisher date