DEBIAN-CVE-2026-13758
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.
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/versions0.078-1Source reference:
/affected/0/versions0.080-1Source reference:
/affected/0/versions0.080-2Source reference:
/affected/0/versions0.081-1Source reference:
/affected/0/versions0.081-2Source reference:
/affected/0/versions0.082-1Source reference:
/affected/0/versions0.082.001-1Source reference:
/affected/0/versions0.084-1Source reference:
/affected/0/versions0.085-1Source reference:
/affected/0/versions0.087-1Source reference:
/affected/0/versions0.087-2Source reference:
/affected/0/versions0.088-1Source reference:
/affected/0/versions0.089-1Source reference:
/affected/0/versions0.090-1Source reference:
/affected/0/versions0.090-1~bpo13+1Source reference:
/affected/0/versions0.091-1Source 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/versions0.085-1+deb13u1Source reference:
/affected/1/versions0.087-1Source reference:
/affected/1/versions0.087-2Source reference:
/affected/1/versions0.088-1Source reference:
/affected/1/versions0.089-1Source reference:
/affected/1/versions0.090-1Source reference:
/affected/1/versions0.090-1~bpo13+1Source reference:
/affected/1/versions0.091-1Source 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/versions0.087-1Source reference:
/affected/2/versions0.087-2Source reference:
/affected/2/versions0.088-1Source 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
- Added to Heist Feed
- Publisher date