CVE-2026-53245

Description

In the Linux kernel, the following vulnerability has been resolved: net/802/mrp: fix vector attribute parsing in mrp_pdu_parse_vecattr In mrp_pdu_parse_vecattr(), vector attribute events are encoded three per byte and valen tracks the number of events left to process. The parser decrements valen after processing the first and second events from each event byte, but not after processing the third one. When valen is exactly a multiple of three, the loop continues after the last valid event and consumes the next byte as a new event byte, applying a spurious event to the MRP applicant state. Additionally, when valen is zero the parser unconditionally consumes attrlen bytes as FirstValue and advances the offset, even though per IEEE 802.1ak a VectorAttribute with only a LeaveAllEvent has valen of zero and no FirstValue or Vector fields. This corrupts the offset for subsequent PDU parsing. Also, when valen exceeds three the loop crosses byte boundaries but the attribute value is not incremented between the last event of one byte and the first event of the next. This causes the first event of the next byte to use the same attribute value as the third event rather than the next consecutive value. Decrement valen after processing the third event, skip FirstValue consumption when valen is zero, and increment the attribute value at the end of each loop iteration.

Gravité et risque d'exploitation

CVE-2026-53245 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.*, <=6.12.*, 6.12.94, <36d259711872e3b2f6cd76a4d270c21931c0f35f, <42446ca0f3570663e87183c065e0b4def52dfba2, 0, <3.9, 6.1.176, 5.15.210, <=5.10.*, <=6.6.*, 7.0.13, <6eea6494e542a03cdf755a593b7d74f3f7c260fd, febf018d22347b5df94066bca05d0c11a84e839d, 6.18.36, 7.1, <fd9c3a47c670bec6b18f44454cea023f93b5adb3, <=6.18.*, <7561c7fbc694308da73300f036719e63e42bf0b4, <6d6e42e8e17f18d61327f8653479c5b5e161ae1d, <=*, <=5.15.*, <cc98717e591a963a616fdf15ecf48eefaf45d758, 6.6.143, <ae65714d96f68bb252eb20085320bdaacab36c00, 5.10.259, 3.9) 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

• https://git.kernel.org/stable/c/ae65714d96f68bb252eb20085320bdaacab36c00
• https://git.kernel.org/stable/c/36d259711872e3b2f6cd76a4d270c21931c0f35f
• https://git.kernel.org/stable/c/cc98717e591a963a616fdf15ecf48eefaf45d758
• https://git.kernel.org/stable/c/6d6e42e8e17f18d61327f8653479c5b5e161ae1d
• https://git.kernel.org/stable/c/fd9c3a47c670bec6b18f44454cea023f93b5adb3
• https://git.kernel.org/stable/c/42446ca0f3570663e87183c065e0b4def52dfba2
• https://git.kernel.org/stable/c/6eea6494e542a03cdf755a593b7d74f3f7c260fd
• https://git.kernel.org/stable/c/7561c7fbc694308da73300f036719e63e42bf0b4