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CVE-2026-53402

Vulnérabilité élevée dans Linux (Linux)

CVSS 7.1 · Élevée
EPSS 0.1%
Linux•Linux•Versions : <=6.1.*, <=6.12.*, 6.18.39, <5.15.212, 0, ebd6f886aa2447fcfcdce5450c9e1028e1d681bb, <cb016bcb40c81e7b19c4ae6143babb366dae8e20, <=7.1.*, 5.15.64, 6.1.178, <=5.10.*, <=6.6.*, 6.0, <39815715cbcfabb16fc8c5f4a23deeda20f5df62, 5.10.249, <6.0, <a7a526fbc847f07ad3a503c7382189be5ab68574, <ac562193c36696513ae196171892e9338475c4bc, <=6.18.*, 5.15.212, 6.6.145, 5.10.261, 5.19.6, <5.20, a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24, <5.10.261, <8fdc8c2057eea08d40ce2c8eed41ff9e451c65c2, <b5bb2c696e140c399cb874def2feedf61dee27d6, 868749a7456dc48e93887a8474194e2ee6d6c21f, <=*, <=5.15.*, 7.1.3, f08ccb792d3eaf1dc62d8cbf6a30d6522329f660, 6.12.96, <3618a4c5b2591cfa83efe74f5b18c2d02b35c3f5, 7.2, <076b1aa65f77a49bce5a48a4a55a397cfcafa2b8

Description

In the Linux kernel, the following vulnerability has been resolved: fbdev: fbcon: fix out-of-bounds read in err_out of fbcon_do_set_font() When fbcon_do_set_font() fails (e.g., due to a memory allocation failure inside vc_resize() under heavy memory pressure), it jumps to the `err_out` label to roll back the console state. However, the current rollback logic forgets to restore the `hi_font` state, leading to a severe state machine corruption. Earlier in the function, `set_vc_hi_font()` might be called to change `vc->vc_hi_font_mask` and mutate the screen buffer. If `vc_resize()` subsequently fails, the `err_out` path restores `vc_font.charcount` but entirely skips rolling back the `vc_hi_font_mask` and the screen buffer. This mismatch leaves the terminal in a desynchronized state. Because `vc_hi_font_mask` remains set, the VT subsystem will still accept character indices greater than 255 from userspace and write them to the screen buffer. Subsequent rendering calls (e.g., `fbcon_putcs()`) will then use these inflated indices to access the reverted, 256-character font array, leading to a deterministic out-of-bounds read and potential kernel memory disclosure. Fix this by adding the missing rollback logic for the `hi_font` mask and screen buffer in the error path.

Gravité et risque d'exploitation

CVE-2026-53402 obtient un score CVSS de 7.1/10, 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 2.7 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, <=6.12.*, 6.18.39, <5.15.212, 0, ebd6f886aa2447fcfcdce5450c9e1028e1d681bb, <cb016bcb40c81e7b19c4ae6143babb366dae8e20, <=7.1.*, 5.15.64, 6.1.178, <=5.10.*, <=6.6.*, 6.0, <39815715cbcfabb16fc8c5f4a23deeda20f5df62, 5.10.249, <6.0, <a7a526fbc847f07ad3a503c7382189be5ab68574, <ac562193c36696513ae196171892e9338475c4bc, <=6.18.*, 5.15.212, 6.6.145, 5.10.261, 5.19.6, <5.20, a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24, <5.10.261, <8fdc8c2057eea08d40ce2c8eed41ff9e451c65c2, <b5bb2c696e140c399cb874def2feedf61dee27d6, 868749a7456dc48e93887a8474194e2ee6d6c21f, <=*, <=5.15.*, 7.1.3, f08ccb792d3eaf1dc62d8cbf6a30d6522329f660, 6.12.96, <3618a4c5b2591cfa83efe74f5b18c2d02b35c3f5, 7.2, <076b1aa65f77a49bce5a48a4a55a397cfcafa2b8) 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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