CVE-2026-23095

Vulnérabilité élevée dans Linux (Linux)

CVSS 7.5 · Élevée
EPSS 0.3%
Linux•Linux•Versions : <=6.1.*, <=6.12.*, 37dd0247797b168ad1cc7f5dbec825a1ee66535b, <380a82d36e37db49fd41ecc378c22fd29392e96a, 0, 5.15.199, <f87b9b7a618c82e7465e872eb10e14c803871892, <=5.10.*, <=6.6.*, 5.10.249, <9a56796ad258786d3624eef5aefba394fc9bdded, 6.18.8, 6.1.162, <=6.18.*, <536f5bbc322eb1e175bdd1ced22b236a951c4d8f, <ce569b389a5c78d64788a5ea94560e17fa574b35, <3.18, <886f186328b718400dbf79e1bc8cbcbd710ab766, 6.12.68, <=*, <=5.15.*, 6.19, 6.6.122, 3.18, <5437a279804ced8088cabb945dba88a26d828f8c

Description

In the Linux kernel, the following vulnerability has been resolved: gue: Fix skb memleak with inner IP protocol 0. syzbot reported skb memleak below. [0] The repro generated a GUE packet with its inner protocol 0. gue_udp_recv() returns -guehdr->proto_ctype for "resubmit" in ip_protocol_deliver_rcu(), but this only works with non-zero protocol number. Let's drop such packets. Note that 0 is a valid number (IPv6 Hop-by-Hop Option). I think it is not practical to encap HOPOPT in GUE, so once someone starts to complain, we could pass down a resubmit flag pointer to distinguish two zeros from the upper layer: * no error * resubmit HOPOPT [0] BUG: memory leak unreferenced object 0xffff888109695a00 (size 240): comm "syz.0.17", pid 6088, jiffies 4294943096 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 40 c2 10 81 88 ff ff 00 00 00 00 00 00 00 00 .@.............. backtrace (crc a84b336f): kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline] slab_post_alloc_hook mm/slub.c:4958 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x3b4/0x590 mm/slub.c:5270 __build_skb+0x23/0x60 net/core/skbuff.c:474 build_skb+0x20/0x190 net/core/skbuff.c:490 __tun_build_skb drivers/net/tun.c:1541 [inline] tun_build_skb+0x4a1/0xa40 drivers/net/tun.c:1636 tun_get_user+0xc12/0x2030 drivers/net/tun.c:1770 tun_chr_write_iter+0x71/0x120 drivers/net/tun.c:1999 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x45d/0x710 fs/read_write.c:686 ksys_write+0xa7/0x170 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Gravité et risque d'exploitation

CVE-2026-23095 obtient un score CVSS de 7.5/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.30 %, ce qui la place devant 21.2 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, <=6.12.*, 37dd0247797b168ad1cc7f5dbec825a1ee66535b, <380a82d36e37db49fd41ecc378c22fd29392e96a, 0, 5.15.199, <f87b9b7a618c82e7465e872eb10e14c803871892, <=5.10.*, <=6.6.*, 5.10.249, <9a56796ad258786d3624eef5aefba394fc9bdded, 6.18.8, 6.1.162, <=6.18.*, <536f5bbc322eb1e175bdd1ced22b236a951c4d8f, <ce569b389a5c78d64788a5ea94560e17fa574b35, <3.18, <886f186328b718400dbf79e1bc8cbcbd710ab766, 6.12.68, <=*, <=5.15.*, 6.19, 6.6.122, 3.18, <5437a279804ced8088cabb945dba88a26d828f8c) 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