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CVE-2026-53208

Vulnérabilité non évaluée dans Linux (Linux)

CVSS 0.0 · Non évaluée
EPSS 0.1%
Linux•Linux•Versions : <=6.1.*, <=7.0.*, <e2b8acf9405bd9b1baf1c54dc897b0905db689bf, <=6.12.*, 6.12.94, 2.6.12, <e05c4ac575b457978a7ef441053394169084869c, 0, <a8335f3db15bd1e0e82e0db5d488fabc7d10d1ab, 6.1.176, <2.6.12, <fa5823126239b3e453fac1a2fe50726c7f4a55e1, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 5.15.210, <=5.10.*, <=6.6.*, <dedc92b96dc1d8919a3bdf2495ede68922ef7ebc, 7.0.13, 6.18.36, 7.1, <=6.18.*, <214a2042b16b3c8d798a8b9ef9f36094f13a9859, <=*, <=5.15.*, <dd214733544427587a95f66dbf3adff072568990, 6.6.143, <b20e8a98dd29b121f58fcdf51e8576119aba536a, 5.10.259

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: reject BR/EDR signaling packets over MTUsig net/bluetooth/l2cap_core.c:l2cap_sig_channel() accepts BR/EDR signaling packets up to the channel MTU and dispatches each command without enforcing the signaling MTU (MTUsig). A Bluetooth BR/EDR peer within radio range can send a fixed-channel CID 0x0001 packet that is larger than MTUsig and contains many L2CAP_ECHO_REQ commands before pairing. In a real-radio stock-kernel run, one 681-byte signaling packet containing 168 zero-length ECHO_REQ commands made the target transmit 168 ECHO_RSP frames over about 220 ms. Impact: a Bluetooth BR/EDR peer within radio range, before pairing, can force 168 ECHO_RSP frames from one 681-byte fixed-channel signaling packet containing packed ECHO_REQ commands. Define Linux's BR/EDR signaling MTU as the spec minimum of 48 bytes and reject any larger signaling packet with one L2CAP_COMMAND_REJECT_RSP carrying L2CAP_REJ_MTU_EXCEEDED before any command is dispatched. The Bluetooth Core spec wording for MTUExceeded says the reject identifier shall match the first request command in the packet, and that packets containing only responses shall be silently discarded. Linux intentionally deviates from that prescription: silently discarding desynchronizes the peer because the remote stack never learns its responses were dropped, and locating the first request command requires walking command headers past MTUsig, i.e. processing bytes from a packet we have already decided is too large to process. We therefore always emit one reject and use the identifier from the first command header, a single fixed-offset byte read. The unrestricted BR/EDR signaling parser and ECHO_REQ response path both trace to the initial git import; no later introducing commit is available for a Fixes tag.

Gravité et risque d'exploitation

CVE-2026-53208 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 0.13 %, ce qui la place devant 2.0 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, <=7.0.*, <e2b8acf9405bd9b1baf1c54dc897b0905db689bf, <=6.12.*, 6.12.94, 2.6.12, <e05c4ac575b457978a7ef441053394169084869c, 0, <a8335f3db15bd1e0e82e0db5d488fabc7d10d1ab, 6.1.176, <2.6.12, <fa5823126239b3e453fac1a2fe50726c7f4a55e1, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 5.15.210, <=5.10.*, <=6.6.*, <dedc92b96dc1d8919a3bdf2495ede68922ef7ebc, 7.0.13, 6.18.36, 7.1, <=6.18.*, <214a2042b16b3c8d798a8b9ef9f36094f13a9859, <=*, <=5.15.*, <dd214733544427587a95f66dbf3adff072568990, 6.6.143, <b20e8a98dd29b121f58fcdf51e8576119aba536a, 5.10.259) 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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