GHSA-F7W2-RJ2F-73Q3
Vulnerability from github – Published: 2026-05-27 15:33 – Updated: 2026-09-08 09:35In the Linux kernel, the following vulnerability has been resolved:
crypto: authencesn - reject short ahash digests during instance creation
authencesn requires either a zero authsize or an authsize of at least 4 bytes because the ESN encrypt/decrypt paths always move 4 bytes of high-order sequence number data at the end of the authenticated data.
While crypto_authenc_esn_setauthsize() already rejects explicit non-zero authsizes in the range 1..3, crypto_authenc_esn_create() still copied auth->digestsize into inst->alg.maxauthsize without validating it. The AEAD core then initialized the tfm's default authsize from that value.
As a result, selecting an ahash with digest size 1..3, such as cbcmac(cipher_null), exposed authencesn instances whose default authsize was invalid even though setauthsize() would have rejected the same value. AF_ALG could then trigger the ESN tail handling with a too-short tag and hit an out-of-bounds access.
Reject authencesn instances whose ahash digest size is in the invalid non-zero range 1..3 so that no tfm can inherit an unsupported default authsize.
{
"affected": [],
"aliases": [
"CVE-2026-46033"
],
"database_specific": {
"cwe_ids": [
"CWE-125",
"CWE-1284"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-05-27T14:17:22Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: authencesn - reject short ahash digests during instance creation\n\nauthencesn requires either a zero authsize or an authsize of at least\n4 bytes because the ESN encrypt/decrypt paths always move 4 bytes of\nhigh-order sequence number data at the end of the authenticated data.\n\nWhile crypto_authenc_esn_setauthsize() already rejects explicit\nnon-zero authsizes in the range 1..3, crypto_authenc_esn_create()\nstill copied auth-\u003edigestsize into inst-\u003ealg.maxauthsize without\nvalidating it. The AEAD core then initialized the tfm\u0027s default\nauthsize from that value.\n\nAs a result, selecting an ahash with digest size 1..3, such as\ncbcmac(cipher_null), exposed authencesn instances whose default\nauthsize was invalid even though setauthsize() would have rejected the\nsame value. AF_ALG could then trigger the ESN tail handling with a\ntoo-short tag and hit an out-of-bounds access.\n\nReject authencesn instances whose ahash digest size is in the invalid\nnon-zero range 1..3 so that no tfm can inherit an unsupported default\nauthsize.",
"id": "GHSA-f7w2-rj2f-73q3",
"modified": "2026-09-08T09:35:29Z",
"published": "2026-05-27T15:33:21Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46033"
},
{
"type": "WEB",
"url": "https://access.redhat.com/security/cve/CVE-2026-46033"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2482000"
},
{
"type": "WEB",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2f31cd1e64a079c845bca31d2da7b3c90a311726"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5db6ef9847717329f12c5ea8aba7e9f588a980c0"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/67f1f0933cc3d78dde222842bcad2778ec7a0b88"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/77f59fb2d3aa33e90ec6cbbf45dcfb20ab82b1a9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9aff81e8217e9de2929084b03b3c7f81988c112b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b42821c15445f93daea3e76ada682b2b7181c476"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b69933e97efea238ebbfcf70c2b1be1cd03f13e3"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d4c6a6d08e70bb1083c7c405fc7faacbf19aebc0"
},
{
"type": "WEB",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46033.json"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
"type": "CVSS_V3"
}
]
}
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