CVE-2026-98454
Vulnérabilité non évaluée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix create context out-of-bounds reads smb2_parse_contexts() validates the complete create-context area but does not limit each record to its Next field before dispatching it. A malformed chain can therefore expose bytes beyond the current context to a handler. The QFid handler also used a full response-structure cast although it only reads DiskFileId. The SMB2/SMB3 lease parsers made the same layout assumption: they read LeaseState and LeaseFlags at canonical offsets rather than at DataOffset. A valid non-canonical DataOffset could therefore yield unrelated in-bounds data, while a short DataLength was still accepted. Limit each context to its Next value, reject offsets before the context header, and reject malformed chains. Bound the name range by the current context and do not dispatch a known handler when DataLength is zero. Read the QFid DiskFileId only when the context data covers that field. Parse the lease context from DataOffset and require DataLength to match the v1 or v2 lease_context size used by ksmbd. A size mismatch skips lease parsing without failing the open.
Gravité et risque d'exploitation
CVE-2026-98454 obtient un score CVSS de 0.0/10, soit une gravité non évaluée.
Que faire ?
- Vérifiez si Linux (versions <=6.12.*, 6.18.55, 0, b8c32dbb0deb287a5fcb78251e4eae6c7275760d, <cecc5399987e73a528ce2b662eeb54af69163cbd, 6.12.112, 6.6.158, <=6.6.*, <e4c49012708c917eafd9c27054b02d0f8b30fe64, <=6.18.*, <67f4c1c6a1b51e203d986779299824d1c2c590a6, <28bc9a871799363afa3139e961a8e3684feb8704, <=7.2.*, <3.7, 7.2.9, <05a7fd80024ff32b9b40ab1478bb172eeab1c386, <=*, 3.7, 7.3) 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/e4c49012708c917eafd9c27054b02d0f8b30fe64
- https://git.kernel.org/stable/c/28bc9a871799363afa3139e961a8e3684feb8704
- https://git.kernel.org/stable/c/05a7fd80024ff32b9b40ab1478bb172eeab1c386
- https://git.kernel.org/stable/c/cecc5399987e73a528ce2b662eeb54af69163cbd
- https://git.kernel.org/stable/c/67f4c1c6a1b51e203d986779299824d1c2c590a6