DEBIAN-CVE-2026-42765
Issue summary: When a partial-chain certificate verification is enabled together with OCSP response checking for the whole chain, a NULL dereference will happen if the verified chain does not have a self-signed trusted anchor, crashing the process. Impact summary: A NULL pointer dereference can trigger a crash which leads to a Denial of Service for an application. When performing OCSP response checking for certificates in the verification chain, the code always tries to access the next certificate as the issuer. There is a check for a self-signed certificate. However with the partial chain verification enabled when the chain does not have a self-signed trusted anchor, the issuer will be NULL for the last certificate in the chain. A NULL pointer dereference then happens. This issue affects only applications which enable both OCSP verification of the certificate chain (X509_V_FLAG_OCSP_RESP_CHECK_ALL) and partial chain verification (X509_V_FLAG_PARTIAL_CHAIN) in the certificate verification. Both flags are disabled by default. For that reason, we have assigned Low severity to the issue. No FIPS modules are affected by this issue as the affected code is outside the OpenSSL FIPS module boundary.
DEBIAN-CVE-2026-42765
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: osv:DEBIAN-CVE-2026-42765
openssl
Source reference: /affected/0/package/name
- Affected versions
- 3.5.1-1
Source reference:
/affected/0/versions3.5.2-1Source reference:
/affected/0/versions3.5.3-1Source reference:
/affected/0/versions3.5.4-1Source reference:
/affected/0/versions3.5.4-1~deb13u1Source reference:
/affected/0/versions3.5.4-1~deb13u2Source reference:
/affected/0/versions3.5.5-1Source reference:
/affected/0/versions3.5.5-1~deb13u1Source reference:
/affected/0/versions3.5.5-1~deb13u2Source reference:
/affected/0/versions3.5.6-1~deb13u1Source reference:
/affected/0/versions3.5.6-1~deb13u2Source reference:
/affected/0/versions3.5.7-1~deb13u1Source reference:
/affected/0/versions3.5.7-1~deb13u2Source reference:
/affected/0/versions3.5.7-1~deb13u3Source reference:
/affected/0/versions3.6.0-1Source reference:
/affected/0/versions3.6.0-2Source reference:
/affected/0/versions3.6.0~~alpha1-1Source reference:
/affected/0/versions3.6.0~~beta1-1Source reference:
/affected/0/versions3.6.1-1Source reference:
/affected/0/versions3.6.1-2Source reference:
/affected/0/versions3.6.1-3Source reference:
/affected/0/versions3.6.2-1Source reference:
/affected/0/versions - Fixed versions
- 3.6.3-1
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "3.6.3-1"
}
]
}
],
"package": {
"name": "openssl",
"purl": "pkg:deb/debian/openssl?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"3.5.1-1",
"3.5.2-1",
"3.5.3-1",
"3.5.4-1",
"3.5.4-1~deb13u1",
"3.5.4-1~deb13u2",
"3.5.5-1",
"3.5.5-1~deb13u1",
"3.5.5-1~deb13u2",
"3.5.6-1~deb13u1",
"3.5.6-1~deb13u2",
"3.5.7-1~deb13u1",
"3.5.7-1~deb13u2",
"3.5.7-1~deb13u3",
"3.6.0-1",
"3.6.0-2",
"3.6.0~~alpha1-1",
"3.6.0~~beta1-1",
"3.6.1-1",
"3.6.1-2",
"3.6.1-3",
"3.6.2-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-42765.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #56065 · Revision 1
- Added to Heist Feed
- Publisher date