High [CVE-2026-89633] Linux kernel SMB client: Out-of-bounds read/write via unvalidated DataOffset
This high-severity Red Hat Linux advisory covers CVE-2026-89633.
Android app · Google Play
Monitor future Red Hat Linux CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 32 official vendor sources and 160+ reviewed platform categories.
Summary
A flaw was found in the Linux kernel's Server Message Block (SMB) client. The `coalesce_t2()` function processes server-supplied `DataOffset` fields without proper validation against buffer boundaries.
A remote attacker could exploit this by crafting malicious SMB responses. This could lead to out-of-bounds read and write operations, potentially resulting in information disclosure or arbitrary code execution.
Red Hat severity: Important — CVSS 7.1 (CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H). Weakness: CWE-125.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · medium-confidence parse· fetched 26 minutes ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 26 minutes ago·verify at source
Mitigation
The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 26 minutes ago·verify at source
Discussion(0)
No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.
Sign in to join the discussion.