DEBIAN-CVE-2026-6291
Bleichenbacher padding oracle in PKCS#7 KTRI decryption. When decrypting PKCS#7 EnvelopedData using RSA PKCS#1 v1.5 key transport, wolfSSL returned distinguishable error codes depending on whether RSA padding validation failed versus whether the decrypted content was malformed. An attacker able to submit crafted EnvelopedData messages and observe error responses could use this as a padding oracle to incrementally recover the encrypted Content Encryption Key (CEK). The fix generates a deterministic pseudo-random fake CEK on padding failure (via HMAC-SHA256) and proceeds with decryption identically, using constant-time operations throughout, so that all failure paths produce the same error regardless of padding validity.
DEBIAN-CVE-2026-6291
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-2026-6291
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/versions5.5.4-2+deb12u3Source reference:
/affected/0/versions5.5.4-2.1Source reference:
/affected/0/versions5.6.4-1Source reference:
/affected/0/versions5.6.4-2Source reference:
/affected/0/versions5.6.6-1Source reference:
/affected/0/versions5.6.6-1.1Source reference:
/affected/0/versions5.6.6-1.2Source reference:
/affected/0/versions5.6.6-1.3Source reference:
/affected/0/versions5.6.6-1.3~exp1Source reference:
/affected/0/versions5.7.0-0.1Source reference:
/affected/0/versions5.7.0-0.2Source reference:
/affected/0/versions5.7.0-0.3Source reference:
/affected/0/versions5.7.2-0.1Source reference:
/affected/0/versions5.7.2-0.2Source reference:
/affected/0/versions5.7.2-0.3Source reference:
/affected/0/versions5.7.2-0.4Source reference:
/affected/0/versions5.8.2-1Source reference:
/affected/0/versions5.8.2-1.1Source reference:
/affected/0/versions5.8.2-1.2Source reference:
/affected/0/versions5.8.4-1Source reference:
/affected/0/versions5.9.0-0.1Source reference:
/affected/0/versions5.9.0-0.2Source reference:
/affected/0/versions5.9.1-0.1Source reference:
/affected/0/versions5.9.2-1Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- 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/versions5.7.2-0.1+deb13u2Source reference:
/affected/1/versions5.7.2-0.2Source reference:
/affected/1/versions5.7.2-0.3Source reference:
/affected/1/versions5.7.2-0.4Source reference:
/affected/1/versions5.8.2-1Source reference:
/affected/1/versions5.8.2-1.1Source reference:
/affected/1/versions5.8.2-1.2Source reference:
/affected/1/versions5.8.4-1Source reference:
/affected/1/versions5.9.0-0.1Source reference:
/affected/1/versions5.9.0-0.2Source reference:
/affected/1/versions5.9.1-0.1Source reference:
/affected/1/versions5.9.2-1Source reference:
/affected/1/versions - 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.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"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",
"5.5.4-2+deb12u3",
"5.5.4-2.1",
"5.6.4-1",
"5.6.4-2",
"5.6.6-1",
"5.6.6-1.1",
"5.6.6-1.2",
"5.6.6-1.3",
"5.6.6-1.3~exp1",
"5.7.0-0.1",
"5.7.0-0.2",
"5.7.0-0.3",
"5.7.2-0.1",
"5.7.2-0.2",
"5.7.2-0.3",
"5.7.2-0.4",
"5.8.2-1",
"5.8.2-1.1",
"5.8.2-1.2",
"5.8.4-1",
"5.9.0-0.1",
"5.9.0-0.2",
"5.9.1-0.1",
"5.9.2-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-6291.json"
},
"ecosystem_specific": {
"urgency": "end-of-life"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"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",
"5.7.2-0.1+deb13u2",
"5.7.2-0.2",
"5.7.2-0.3",
"5.7.2-0.4",
"5.8.2-1",
"5.8.2-1.1",
"5.8.2-1.2",
"5.8.4-1",
"5.9.0-0.1",
"5.9.0-0.2",
"5.9.1-0.1",
"5.9.2-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-6291.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #58093 · Revision 1
- Added to Heist Feed
- Publisher date