DEBIAN-CVE-2026-55962
TLS 1.3 post-handshake authentication (PHA) issue where a server could accept a client's Finished message without the client having sent a Certificate and CertificateVerify. The post-handshake-auth exemption that allows an empty/absent peer certificate was only intended for the initial handshake, but it was also being applied while a post-handshake CertificateRequest was still outstanding. The check is now scoped to the initial handshake only: on the server, once a post-handshake CertificateRequest has been sent (certReqCtx is set), a peer certificate and a valid CertificateVerify are required again before the Finished is accepted, with empty-certificate handling following the configured verify mode (FAIL_IF_NO_PEER_CERT) just as during first-handshake client authentication. Only affects TLS 1.3 servers built with post-handshake authentication support (WOLFSSL_POST_HANDSHAKE_AUTH / --enable-postauth, included in --enable-all) that enable WOLFSSL_VERIFY_POST_HANDSHAKE and request a client certificate after the handshake via wolfSSL_request_certificate(). Clients, and servers that do not use post-handshake authentication, are unaffected.
DEBIAN-CVE-2026-55962
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-2026-55962
wolfssl
Source reference: /affected/0/package/name
- Affected versions
- 5.5.4-2
Source reference:
/affected/0/versions5.5.4-2+deb12u1Source reference:
/affected/0/versions5.5.4-2+deb12u2Source reference:
/affected/0/versions - Fixed versions
- 5.5.4-2+deb12u3
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
wolfssl
Source reference: /affected/1/package/name
- Affected versions
- 5.7.2-0.1
Source reference:
/affected/1/versions5.7.2-0.1+deb13u1Source reference:
/affected/1/versions - Fixed versions
- 5.7.2-0.1+deb13u2
Source reference:
/affected/1/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": "5.5.4-2+deb12u3"
}
]
}
],
"package": {
"name": "wolfssl",
"purl": "pkg:deb/debian/wolfssl?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"5.5.4-2",
"5.5.4-2+deb12u1",
"5.5.4-2+deb12u2"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-55962.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.7.2-0.1+deb13u2"
}
]
}
],
"package": {
"name": "wolfssl",
"purl": "pkg:deb/debian/wolfssl?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"5.7.2-0.1",
"5.7.2-0.1+deb13u1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-55962.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #57866 · Revision 1
- Added to Heist Feed
- Publisher date