CVE-2026-63796
OCFS2 bitmap descriptor flaw allows kernel memory corruption
Is CVE-2026-63796 being exploited?
Not confirmed. CVE-2026-63796 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.48% probability of exploitation in the next 30 days.
How severe is CVE-2026-63796?
CVE-2026-63796 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-63796?
Yes. A fix has been recorded for CVE-2026-63796. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-63796 affect?
CVE-2026-63796 affects Linux kernel (OCFS2 module), Systems mounting OCFS2 volumes, Clustered Linux nodes using OCFS2. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-63796?
Apply vendor kernel/OCFS2 patch and unmount OCFS2 volumes until updated.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Out-of-bounds bitmap access in OCFS2 can crash the kernel or enable local privilege escalation when processing a crafted OCFS2 volume.
Immediate action required
- affected>= ccd979bdbce9fba8412beb3f1de68a9d0171b12c and < 336340a0f8a141df8a4eb21a5a86f8ffb87769f6
- affected>= ccd979bdbce9fba8412beb3f1de68a9d0171b12c and < 296c6a42b1174395935ca4cfe8f393e37b698d54
- affected>= ccd979bdbce9fba8412beb3f1de68a9d0171b12c and < d2cd59fa848f9f13796ef214d3b1b5ca9a3fe21e
- affected>= ccd979bdbce9fba8412beb3f1de68a9d0171b12c and < c5a125eadba05ba421c4b55e68da22b4a40d32b4
- affected>= ccd979bdbce9fba8412beb3f1de68a9d0171b12c and < 8f9903b0cdbb3155a8899410330b4b4d583a7a5c
- affected>= ccd979bdbce9fba8412beb3f1de68a9d0171b12c and < 4cd57ebee395041099fcdfcabb00749ce38d8b27
- affected>= ccd979bdbce9fba8412beb3f1de68a9d0171b12c and < 99c21e7263248c3f084756bfae08163cc5d6c62f
- affected>= ccd979bdbce9fba8412beb3f1de68a9d0171b12c and < 9bd541e09dffff27e5bec0f9f45b0228173a5375
- affected2.6.16
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.