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DEBIAN-CVE-2026-13758

Type: advisorySource: OSV1 source record

CryptX versions before 0.088_001 for Perl compare AEAD authentication tags in non-constant time in the streaming decrypt_done path. The decrypt_done($tag) form compares it against the computed tag with memNE (memcmp() != 0), which short-circuits on the first differing byte, so its run time depends on the number of matching leading bytes. This affects all five AEAD modes: GCM, CCM, ChaCha20Poly1305, EAX and OCB. The one-shot *_decrypt_verify helpers are unaffected; they verify the tag inside libtomcrypt with a constant-time comparison. The timing difference is a tag-verification oracle. An attacker who can submit many candidate tags for the same nonce, ciphertext and associated data while measuring the timing precisely enough may recover the expected tag byte by byte and forge a message that verifies.

Announced Source revision 1
Original source ↗

DEBIAN-CVE-2026-13758

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-2026-13758

libcryptx-perl

Source reference: /affected/0/package/name

Affected versions
0.077-1

Source reference: /affected/0/versions

0.078-1

Source reference: /affected/0/versions

0.080-1

Source reference: /affected/0/versions

0.080-2

Source reference: /affected/0/versions

0.081-1

Source reference: /affected/0/versions

0.081-2

Source reference: /affected/0/versions

0.082-1

Source reference: /affected/0/versions

0.082.001-1

Source reference: /affected/0/versions

0.084-1

Source reference: /affected/0/versions

0.085-1

Source reference: /affected/0/versions

0.087-1

Source reference: /affected/0/versions

0.087-2

Source reference: /affected/0/versions

0.088-1

Source reference: /affected/0/versions

0.089-1

Source reference: /affected/0/versions

0.090-1

Source reference: /affected/0/versions

0.090-1~bpo13+1

Source reference: /affected/0/versions

0.091-1

Source reference: /affected/0/versions

Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

libcryptx-perl

Source reference: /affected/1/package/name

Affected versions
0.085-1

Source reference: /affected/1/versions

0.085-1+deb13u1

Source reference: /affected/1/versions

0.087-1

Source reference: /affected/1/versions

0.087-2

Source reference: /affected/1/versions

0.088-1

Source reference: /affected/1/versions

0.089-1

Source reference: /affected/1/versions

0.090-1

Source reference: /affected/1/versions

0.090-1~bpo13+1

Source reference: /affected/1/versions

0.091-1

Source reference: /affected/1/versions

Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

libcryptx-perl

Source reference: /affected/2/package/name

Affected versions
0.085-1

Source reference: /affected/2/versions

0.087-1

Source reference: /affected/2/versions

0.087-2

Source reference: /affected/2/versions

0.088-1

Source reference: /affected/2/versions

Fixed versions
0.089-1

Source reference: /affected/2/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"
          }
        ]
      }
    ],
    "package": {
      "name": "libcryptx-perl",
      "purl": "pkg:deb/debian/libcryptx-perl?arch=source&distro=bookworm",
      "ecosystem": "Debian:12"
    },
    "versions": [
      "0.077-1",
      "0.078-1",
      "0.080-1",
      "0.080-2",
      "0.081-1",
      "0.081-2",
      "0.082-1",
      "0.082.001-1",
      "0.084-1",
      "0.085-1",
      "0.087-1",
      "0.087-2",
      "0.088-1",
      "0.089-1",
      "0.090-1",
      "0.090-1~bpo13+1",
      "0.091-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-13758.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          }
        ]
      }
    ],
    "package": {
      "name": "libcryptx-perl",
      "purl": "pkg:deb/debian/libcryptx-perl?arch=source&distro=trixie",
      "ecosystem": "Debian:13"
    },
    "versions": [
      "0.085-1",
      "0.085-1+deb13u1",
      "0.087-1",
      "0.087-2",
      "0.088-1",
      "0.089-1",
      "0.090-1",
      "0.090-1~bpo13+1",
      "0.091-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-13758.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "0.089-1"
          }
        ]
      }
    ],
    "package": {
      "name": "libcryptx-perl",
      "purl": "pkg:deb/debian/libcryptx-perl?arch=source&distro=forky",
      "ecosystem": "Debian:14"
    },
    "versions": [
      "0.085-1",
      "0.087-1",
      "0.087-2",
      "0.088-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-13758.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  }
]

Publisher severity

No explicit severity was provided.

Event
#55395 · Revision 1
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Publisher date
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