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CVE-2026-80731

Vulnérabilité élevée dans Linux (Linux)

CVSS 7.8 · Élevée
EPSS 0.1%
Linux•Linux•Versions : <=6.1.*, <99df6b7a713f96eda206680d100b76e15f9d9b69, <=6.12.*, <4.2, 3.16.36, 6.6.152, <3b9a324e646d3657a8d9806dfbfe4f3e4066e882, 4.4.8, 4.1.28, 0, <4.6, <=7.1.*, <b0f92a5731dc82556a9ae005cc35f71ab136307b, <dbb30dc943a93e083f1e531bfdc6779e57de40d0, 5.15.216, 2793a23aacbd754dbbb5cb75093deb7e4103bace, <=5.10.*, <=6.6.*, 7.1.9, 1df16498dfd0d5a129bdf2982d9a08df73e8923d, 3.2.81, <fa6d98dd925e72fc028b26a0cbbff9d2f0601ff6, 6804052fa9d86e9a512c88b24a5debbfc1a490fc, <4.5, 8b8d278aa4de9335682bbd4a3bb619af015c859e, 6.1.183, 4.6, <8fc9816404166a90ed8d544dc52482fafffb6d9f, <74e035f07f53feca09e2352e77fccb09cad5e208, <=6.18.*, 6.12.104, f58a6c08ebdfa978178bbca78c2ba744a2665912, 6.18.45, <=3.2.*, 3.2.80, <=*, b5518429e70cd783b8ca52335456172c1a0589f6, <=5.15.*, <3.17, <fc902f52a02298c7432b2334c0c82a2885a1a8b6, 4.5.2, <53fd7f912c0877647d6a1e1877f5ea8535ee0b4a, 5.10.265, 7.2, <3.2.81

Description

In the Linux kernel, the following vulnerability has been resolved: net: remove CAP_SYS_RAWIO zero-padding in dev_validate_header dev_validate_header() reads dev->hard_header_len directly when zero-padding short link layer headers for CAP_SYS_RAWIO holders: if (capable(CAP_SYS_RAWIO)) { memset(ll_header + len, 0, dev->hard_header_len - len); return true; } Packet send paths call dev_validate_header() on skbs whose headroom was allocated from an earlier hard_header_len read. If the device is reconfigured so that dev->hard_header_len increases before validation, the memset writes past the reserved buffer, an out-of-bounds write. This out-of-bounds write is masked in some SOCK_RAW paths today because the same concurrent increase can first make skb_push() exceed the reserved headroom and trigger skb_under_panic(). Remove the zero-padding branch before making those hard_header_len reads consistent, so the snapshot fixes do not turn a loud panic into a silent overwrite. This path is only reached for variable length L2 protocols, where len < hard_header_len but len >= min_header_len. No remaining in-tree variable length L2 protocol implements header_ops->validate, and the CAP_SYS_RAWIO bypass that zero-pads and accepts short headers has no real value beyond allowing testing of intentionally malformed input. Drop the CAP_SYS_RAWIO branch. The remaining reads of dev->hard_header_len in dev_validate_header() are comparisons only and have no memory safety impact.

Gravité et risque d'exploitation

CVE-2026-80731 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 0.14 %, ce qui la place devant 3.1 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, <99df6b7a713f96eda206680d100b76e15f9d9b69, <=6.12.*, <4.2, 3.16.36, 6.6.152, <3b9a324e646d3657a8d9806dfbfe4f3e4066e882, 4.4.8, 4.1.28, 0, <4.6, <=7.1.*, <b0f92a5731dc82556a9ae005cc35f71ab136307b, <dbb30dc943a93e083f1e531bfdc6779e57de40d0, 5.15.216, 2793a23aacbd754dbbb5cb75093deb7e4103bace, <=5.10.*, <=6.6.*, 7.1.9, 1df16498dfd0d5a129bdf2982d9a08df73e8923d, 3.2.81, <fa6d98dd925e72fc028b26a0cbbff9d2f0601ff6, 6804052fa9d86e9a512c88b24a5debbfc1a490fc, <4.5, 8b8d278aa4de9335682bbd4a3bb619af015c859e, 6.1.183, 4.6, <8fc9816404166a90ed8d544dc52482fafffb6d9f, <74e035f07f53feca09e2352e77fccb09cad5e208, <=6.18.*, 6.12.104, f58a6c08ebdfa978178bbca78c2ba744a2665912, 6.18.45, <=3.2.*, 3.2.80, <=*, b5518429e70cd783b8ca52335456172c1a0589f6, <=5.15.*, <3.17, <fc902f52a02298c7432b2334c0c82a2885a1a8b6, 4.5.2, <53fd7f912c0877647d6a1e1877f5ea8535ee0b4a, 5.10.265, 7.2, <3.2.81) 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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