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DEBIAN-CVE-2026-6291

Type: advisorySource: OSV1 source record

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.

Announced Source revision 1
Original source ↗

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/versions

5.5.4-2+deb12u1

Source reference: /affected/0/versions

5.5.4-2+deb12u2

Source reference: /affected/0/versions

5.5.4-2+deb12u3

Source reference: /affected/0/versions

5.5.4-2.1

Source reference: /affected/0/versions

5.6.4-1

Source reference: /affected/0/versions

5.6.4-2

Source reference: /affected/0/versions

5.6.6-1

Source reference: /affected/0/versions

5.6.6-1.1

Source reference: /affected/0/versions

5.6.6-1.2

Source reference: /affected/0/versions

5.6.6-1.3

Source reference: /affected/0/versions

5.6.6-1.3~exp1

Source reference: /affected/0/versions

5.7.0-0.1

Source reference: /affected/0/versions

5.7.0-0.2

Source reference: /affected/0/versions

5.7.0-0.3

Source reference: /affected/0/versions

5.7.2-0.1

Source reference: /affected/0/versions

5.7.2-0.2

Source reference: /affected/0/versions

5.7.2-0.3

Source reference: /affected/0/versions

5.7.2-0.4

Source reference: /affected/0/versions

5.8.2-1

Source reference: /affected/0/versions

5.8.2-1.1

Source reference: /affected/0/versions

5.8.2-1.2

Source reference: /affected/0/versions

5.8.4-1

Source reference: /affected/0/versions

5.9.0-0.1

Source reference: /affected/0/versions

5.9.0-0.2

Source reference: /affected/0/versions

5.9.1-0.1

Source reference: /affected/0/versions

5.9.2-1

Source 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/versions

5.7.2-0.1+deb13u1

Source reference: /affected/1/versions

5.7.2-0.1+deb13u2

Source reference: /affected/1/versions

5.7.2-0.2

Source reference: /affected/1/versions

5.7.2-0.3

Source reference: /affected/1/versions

5.7.2-0.4

Source reference: /affected/1/versions

5.8.2-1

Source reference: /affected/1/versions

5.8.2-1.1

Source reference: /affected/1/versions

5.8.2-1.2

Source reference: /affected/1/versions

5.8.4-1

Source reference: /affected/1/versions

5.9.0-0.1

Source reference: /affected/1/versions

5.9.0-0.2

Source reference: /affected/1/versions

5.9.1-0.1

Source reference: /affected/1/versions

5.9.2-1

Source 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
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