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CVE-2026-23397

Vulnérabilité non évaluée dans Linux (Linux)

CVSS 0.0 · Non évaluée
EPSS 0.1%
Linux•Linux•Versions : <=6.1.*, <=6.12.*, 6.12.78, 0, 7.0, <3932620c04c2938c93c0890c225960d3d34ba355, <224f4678812e1a7bc8341bcb666773a0aec5ea6f, <aa0574182c46963c3cdb8cde46ec93aca21100d8, <=5.10.*, <=6.6.*, <=6.19.*, <2.6.31, 5.15.203, 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384, <=6.18.*, <4c6aa008b913e808c4f4d3cde36cb1d9bb5967c6, 6.1.167, 2.6.31, <dbdfaae9609629a9569362e3b8f33d0a20fd783c, <=*, 5.10.253, <=5.15.*, 6.19.10, 6.6.130, <ec8bf0571b142f29dc0b68ae2ac3952f7a464b38, <3c11b5c2436a3a5b450612ab160e3a525b28cfb5, 6.18.20, <e9cf17b91e733fec725ebcc0b3098bc5ccd505e0

Description

In the Linux kernel, the following vulnerability has been resolved: nfnetlink_osf: validate individual option lengths in fingerprints nfnl_osf_add_callback() validates opt_num bounds and string NUL-termination but does not check individual option length fields. A zero-length option causes nf_osf_match_one() to enter the option matching loop even when foptsize sums to zero, which matches packets with no TCP options where ctx->optp is NULL: Oops: general protection fault KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:nf_osf_match_one (net/netfilter/nfnetlink_osf.c:98) Call Trace: nf_osf_match (net/netfilter/nfnetlink_osf.c:227) xt_osf_match_packet (net/netfilter/xt_osf.c:32) ipt_do_table (net/ipv4/netfilter/ip_tables.c:293) nf_hook_slow (net/netfilter/core.c:623) ip_local_deliver (net/ipv4/ip_input.c:262) ip_rcv (net/ipv4/ip_input.c:573) Additionally, an MSS option (kind=2) with length < 4 causes out-of-bounds reads when nf_osf_match_one() unconditionally accesses optp[2] and optp[3] for MSS value extraction. While RFC 9293 section 3.2 specifies that the MSS option is always exactly 4 bytes (Kind=2, Length=4), the check uses "< 4" rather than "!= 4" because lengths greater than 4 do not cause memory safety issues -- the buffer is guaranteed to be at least foptsize bytes by the ctx->optsize == foptsize check. Reject fingerprints where any option has zero length, or where an MSS option has length less than 4, at add time rather than trusting these values in the packet matching hot path.

Gravité et risque d'exploitation

CVE-2026-23397 obtient un score CVSS de 0.0/10, soit une gravité non évaluée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.12 %, ce qui la place devant 1.8 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, <=6.12.*, 6.12.78, 0, 7.0, <3932620c04c2938c93c0890c225960d3d34ba355, <224f4678812e1a7bc8341bcb666773a0aec5ea6f, <aa0574182c46963c3cdb8cde46ec93aca21100d8, <=5.10.*, <=6.6.*, <=6.19.*, <2.6.31, 5.15.203, 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384, <=6.18.*, <4c6aa008b913e808c4f4d3cde36cb1d9bb5967c6, 6.1.167, 2.6.31, <dbdfaae9609629a9569362e3b8f33d0a20fd783c, <=*, 5.10.253, <=5.15.*, 6.19.10, 6.6.130, <ec8bf0571b142f29dc0b68ae2ac3952f7a464b38, <3c11b5c2436a3a5b450612ab160e3a525b28cfb5, 6.18.20, <e9cf17b91e733fec725ebcc0b3098bc5ccd505e0) 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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