CVE-2026-43025
Estado: ModificadaAlta (7.3)—
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ctnetlink: ignore explicit helper on new expectations
Use the existing master conntrack helper, anything else is not really supported and it just makes validation more complicated, so just ignore what helper userspace suggests for this expectation.
This was uncovered when validating CTA_EXPECT_CLASS via different helper provided by userspace than the existing master conntrack helper:
Allowing to read kernel memory bytes off the expectation boundary.
CTA_EXPECT_HELP_NAME is still used to offer the helper name to userspace via netlink dump.
Detalles técnicos trazas, registros y código del informe original
BUG: KASAN: slab-out-of-bounds in nf_ct_expect_related_report+0x2479/0x27c0 Read of size 4 at addr ffff8880043fe408 by task poc/102 Call Trace: nf_ct_expect_related_report+0x2479/0x27c0 ctnetlink_create_expect+0x22b/0x3b0 ctnetlink_new_expect+0x4bd/0x5c0 nfnetlink_rcv_msg+0x67a/0x950 netlink_rcv_skb+0x120/0x350
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H
- Puntuación base: 7.3
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.17%
- Percentil entre todas las CVEs puntuadas: 5
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1068Exploitation for Privilege Escalationprivilege escalation85 % - Impacto principal
T1005Data from Local Systemcollection80 %
Vulnerabilidad local (AV:L/PR:L) en el kernel Linux permite lectura de memoria fuera de límites (CWE-125, slab-out-of-bounds), escalando privilegios (I:L/A:H). El atacante con acceso local puede leer datos del kernel y potencialmente elevar privilegios.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
CWE
- CWE-125
Referencias
- https://git.kernel.org/stable/c/0f6c33697ccfac6499d0b7a4dbdec5d3a3a566cd
- https://git.kernel.org/stable/c/187b6ec5229ea93cb04c4f6d3b52efc80f513d0d
- https://git.kernel.org/stable/c/21a04c31db4057deec85fcd6cc63d720b38819c3
- https://git.kernel.org/stable/c/2ea0f35f235f70c133ad61fe05ba013753b978c6
- https://git.kernel.org/stable/c/917b61fa2042f11e2af4c428e43f08199586633a
- https://git.kernel.org/stable/c/e135f8e8212cbed12a03ab8dec77fa1247139897
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
JSON original (NVD)
Mostrar
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ctnetlink: ignore explicit helper on new expectations\n\nUse the existing master conntrack helper, anything else is not really\nsupported and it just makes validation more complicated, so just ignore\nwhat helper userspace suggests for this expectation.\n\nThis was uncovered when validating CTA_EXPECT_CLASS via different helper\nprovided by userspace than the existing master conntrack helper:\n\n BUG: KASAN: slab-out-of-bounds in nf_ct_expect_related_report+0x2479/0x27c0\n Read of size 4 at addr ffff8880043fe408 by task poc/102\n Call Trace:\n nf_ct_expect_related_report+0x2479/0x27c0\n ctnetlink_create_expect+0x22b/0x3b0\n ctnetlink_new_expect+0x4bd/0x5c0\n nfnetlink_rcv_msg+0x67a/0x950\n netlink_rcv_skb+0x120/0x350\n\nAllowing to read kernel memory bytes off the expectation boundary.\n\nCTA_EXPECT_HELP_NAME is still used to offer the helper name to userspace\nvia netlink dump."
}
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