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CVE-2026-74628

Vulnérabilité critique dans Linux (Linux)

CVSS 9.8 · Critique
EPSS 0.5%
Linux•Linux•Versions : <=6.1.*, <=6.12.*, 2.6.12, 5.15.217, 0, 5.10.267, <=7.1.*, <3c4919be5d910db4beebca420953858606fba7d8, <2.6.12, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, <6b79659590f0f82a9b8efd2ffd55ec6399ebfc33, <=5.10.*, <=6.6.*, <e92c7e2b41d1528a830bc64c5e4e46dfa8133dda, 7.1.9, <ba925a2e98ce967a0e71c5bcbcf5dbd3facaf0c8, <2195424c3da2ef1829a63b807e3a900a90e57d85, <1fc9f6d2c7c9fdb341bfe8ca449c990632299ea6, <=6.18.*, 6.1.184, 6.18.45, <=*, <=5.15.*, 6.6.153, 6.12.105, <4bc522b33438fefc3272840ae5988771863a4f1f, 7.2, <fdd9ac50b9b61ef2b2d52c5156aff788be91454d

Description

In the Linux kernel, the following vulnerability has been resolved: net/x25: fix use-after-free of the socket by its timers The x25 timers are armed with mod_timer() and cancelled with timer_delete(), so a pending timer holds no reference on the socket and a cancel does not wait for a callback already running on another CPU. x25_heartbeat_expiry() also rearms unconditionally, so it can reinstall sk->sk_timer after __x25_destroy_socket() has passed its cancel point. The following __sock_put() frees the socket while the timer is still queued, and the next expiry uses freed memory. KASAN reports a slab-use-after-free on the kmalloc-2k object freed by close(). timer_delete_sync() cannot be used here: x25_heartbeat_expiry() and x25_timer_expiry() both reach the cancels from inside the timer they would wait on, through __x25_destroy_socket() and x25_disconnect(). Arm the timers with sk_reset_timer() and cancel them with sk_stop_timer() so that an armed timer owns a reference, and release it in both expiry handlers. Rearm the heartbeat only while sk_hashed(sk) is still true, since __x25_destroy_socket() unlinks the socket before dropping it. Arm the deferred destroy timer the same way and drop its reference in x25_destroy_timer(). Reproduced on net with KASAN, with the heartbeat period shortened so the window recurs. With this patch the reproducer no longer triggers a report and /proc/net/x25 drains. Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>

Gravité et risque d'exploitation

CVE-2026-74628 obtient un score CVSS de 9.8/10, soit une gravité critique. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.50 %, ce qui la place devant 41.5 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, <=6.12.*, 2.6.12, 5.15.217, 0, 5.10.267, <=7.1.*, <3c4919be5d910db4beebca420953858606fba7d8, <2.6.12, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, <6b79659590f0f82a9b8efd2ffd55ec6399ebfc33, <=5.10.*, <=6.6.*, <e92c7e2b41d1528a830bc64c5e4e46dfa8133dda, 7.1.9, <ba925a2e98ce967a0e71c5bcbcf5dbd3facaf0c8, <2195424c3da2ef1829a63b807e3a900a90e57d85, <1fc9f6d2c7c9fdb341bfe8ca449c990632299ea6, <=6.18.*, 6.1.184, 6.18.45, <=*, <=5.15.*, 6.6.153, 6.12.105, <4bc522b33438fefc3272840ae5988771863a4f1f, 7.2, <fdd9ac50b9b61ef2b2d52c5156aff788be91454d) est présent sur votre parc.
  • Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
  • À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
  • Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.

Références

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