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CVE-2026-74660

Vulnérabilité élevée dans Linux (Linux)

CVSS 7.8 · Élevée
EPSS 0.1%
Linux•Linux•Versions : <9d8a94b48b393885e7f876c8ef68ed4da5012078, <=6.1.*, <=6.12.*, 6.6.152, 0, <e2ab7e878bdbe80104c879c31fd2d82a476703b8, <30825970339c107bacaf7f61af90fcdb1f597ca1, <=7.1.*, 5.15.216, <47a119ec8a7e2d5c8c4e86fb1a56c4e696e500fb, <=5.10.*, <394d7939c6b2b9e6bea0844c89efb5913168d898, <=6.6.*, 7.1.9, <6809379a860b9fccbb5435bf08343f6d081ac68d, <2cac4294f184c9bc19ff82552c62b80498694c39, 4.12, 6.1.183, <=6.18.*, 6.12.104, 6.18.45, <=*, <=5.15.*, <4.12, 5.10.265, <3bcce49d617c593c7606083bfdb464a1761fa68d, 7.2, c83fa19603bdaeef17b815713dbbe3230c8a34ee

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: ebt_nflog: pin the NFLOG backend nf_log_unregister() runs after the per-net teardown so its final RCU grace period also drains readers that obtained the logger from a per-net binding. However, ebt_nflog passes an explicit ULOG log type to nf_log_packet() without holding a reference on the selected logger module, unlike the xt_NFLOG and nft_log frontends. An ebtables nflog rule can therefore remain callable while nfnetlink_log is unloaded. The resulting interleaving is: CPU 0 CPU 1 nfnetlink_log_fini() unregister_pernet_subsys() kfree(nfnl_log_pernet(net)) ebt_nflog_tg() nf_log_packet() nfulnl_log_packet() instance_lookup_get_rcu() The global ULOG logger is still registered at this point, so CPU 1 dereferences the per-net state after CPU 0 has freed it. KASAN reported: BUG: KASAN: slab-use-after-free in instance_lookup_get_rcu Read of size 8 at addr ff110001052e6210 by task poc/92 Call Trace: instance_lookup_get_rcu+0x1ce/0x1f0 [nfnetlink_log] nfulnl_log_packet+0x248/0x2fb0 [nfnetlink_log] nf_log_packet+0x204/0x300 ebt_nflog_tg+0x351/0x550 ebt_do_table+0xedf/0x22b0 Allocated by task 90: __kmalloc_noprof+0x186/0x470 ops_init+0x6d/0x420 register_pernet_operations+0x2f6/0x670 register_pernet_subsys+0x23/0x40 Freed by task 93: kfree+0x131/0x3c0 ops_undo_list+0x3e3/0x700 unregister_pernet_operations+0x232/0x490 unregister_pernet_subsys+0x1c/0x30 nfnetlink_log_fini+0x34/0x450 [nfnetlink_log] Acquire the ULOG logger module reference when an ebt_nflog rule is validated and release it when the rule is destroyed. Request the NFLOG backend for legacy callers when needed, matching xt_NFLOG. This prevents module teardown until all ebt_nflog rules have stopped using the logger.

Gravité et risque d'exploitation

CVE-2026-74660 obtient un score CVSS de 7.8/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.13 %, ce qui la place devant 2.0 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <9d8a94b48b393885e7f876c8ef68ed4da5012078, <=6.1.*, <=6.12.*, 6.6.152, 0, <e2ab7e878bdbe80104c879c31fd2d82a476703b8, <30825970339c107bacaf7f61af90fcdb1f597ca1, <=7.1.*, 5.15.216, <47a119ec8a7e2d5c8c4e86fb1a56c4e696e500fb, <=5.10.*, <394d7939c6b2b9e6bea0844c89efb5913168d898, <=6.6.*, 7.1.9, <6809379a860b9fccbb5435bf08343f6d081ac68d, <2cac4294f184c9bc19ff82552c62b80498694c39, 4.12, 6.1.183, <=6.18.*, 6.12.104, 6.18.45, <=*, <=5.15.*, <4.12, 5.10.265, <3bcce49d617c593c7606083bfdb464a1761fa68d, 7.2, c83fa19603bdaeef17b815713dbbe3230c8a34ee) 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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