CVE-2026-43139
In the Linux kernel, the following vulnerability has been resolved:
xfrm6: fix uninitialized saddr in xfrm6_get_saddr()
xfrm6_get_saddr() does not check the return value of ipv6_dev_get_saddr(). When ipv6_dev_get_saddr() fails to find a suitable source address (returns -EADDRNOTAVAIL), saddr->in6 is left uninitialized, but xfrm6_get_saddr() still returns 0 (success).
This causes the caller xfrm_tmpl_resolve_one() to use the uninitialized address in xfrm_state_find(), triggering KMSAN warning:
Fix by checking the return value of ipv6_dev_get_saddr() and propagating the error.
Detalles técnicos trazas, registros y código del informe original
===================================================== BUG: KMSAN: uninit-value in xfrm_state_find+0x2424/0xa940 xfrm_state_find+0x2424/0xa940 xfrm_resolve_and_create_bundle+0x906/0x5a20 xfrm_lookup_with_ifid+0xcc0/0x3770 xfrm_lookup_route+0x63/0x2b0 ip_route_output_flow+0x1ce/0x270 udp_sendmsg+0x2ce1/0x3400 inet_sendmsg+0x1ef/0x2a0 __sock_sendmsg+0x278/0x3d0 __sys_sendto+0x593/0x720 __x64_sys_sendto+0x130/0x200 x64_sys_call+0x332b/0x3e70 do_syscall_64+0xd3/0xf80 entry_SYSCALL_64_after_hwframe+0x77/0x7f Local variable tmp.i.i created at: xfrm_resolve_and_create_bundle+0x3e3/0x5a20 xfrm_lookup_with_ifid+0xcc0/0x3770 =====================================================
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
- Puntuación base: 8.6
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.54%
- Percentil entre todas las CVEs puntuadas: 43
- 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
T1190Exploit Public-Facing Applicationinitial access45 % - Impacto principal
T1499.004Application or System Exploitationimpact70 % - Impacto secundario
T1565.001Stored Data Manipulationimpact35 %
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N indica explotación remota sin privilegios. Memoria no inicializada (CWE-908) causa DoS mediante crash de kernel o corrupción de datos en operaciones XFRM IPsec.
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-908
Referencias
- https://git.kernel.org/stable/c/1799d8abeabc68ec05679292aaf6cba93b343c05
- https://git.kernel.org/stable/c/3dcd1664ac15eee6a690daec7c4ffc59190406f7
- https://git.kernel.org/stable/c/4f28141786e1fe884ce42a5197ba9beed540f0ea
- https://git.kernel.org/stable/c/6535867673bf301d52aa00593a4d1d18cc3922fa
- https://git.kernel.org/stable/c/719918fc88df6da023dfff370cd965151a5afd7f
- https://git.kernel.org/stable/c/c7221e7bd8fc2ef38a0b27be580d9d202281306b
- https://git.kernel.org/stable/c/dc0abce055134cb83b0d981d31ceb20dda419787
- https://git.kernel.org/stable/c/eb2ee15290af14c60b45cf2b73f5687d1d077d9b
JSON original (NVD)
Mostrar
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm6: fix uninitialized saddr in xfrm6_get_saddr()\n\nxfrm6_get_saddr() does not check the return value of\nipv6_dev_get_saddr(). When ipv6_dev_get_saddr() fails to find a suitable\nsource address (returns -EADDRNOTAVAIL), saddr->in6 is left\nuninitialized, but xfrm6_get_saddr() still returns 0 (success).\n\nThis causes the caller xfrm_tmpl_resolve_one() to use the uninitialized\naddress in xfrm_state_find(), triggering KMSAN warning:\n\n=====================================================\nBUG: KMSAN: uninit-value in xfrm_state_find+0x2424/0xa940\n xfrm_state_find+0x2424/0xa940\n xfrm_resolve_and_create_bundle+0x906/0x5a20\n xfrm_lookup_with_ifid+0xcc0/0x3770\n xfrm_lookup_route+0x63/0x2b0\n ip_route_output_flow+0x1ce/0x270\n udp_sendmsg+0x2ce1/0x3400\n inet_sendmsg+0x1ef/0x2a0\n __sock_sendmsg+0x278/0x3d0\n __sys_sendto+0x593/0x720\n __x64_sys_sendto+0x130/0x200\n x64_sys_call+0x332b/0x3e70\n do_syscall_64+0xd3/0xf80\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nLocal variable tmp.i.i created at:\n xfrm_resolve_and_create_bundle+0x3e3/0x5a20\n xfrm_lookup_with_ifid+0xcc0/0x3770\n=====================================================\n\nFix by checking the return value of ipv6_dev_get_saddr() and propagating\nthe error."
}
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