Is CVE-2026-98868 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-98868 being exploited in the wild.

How severe is CVE-2026-98868?

Informational severity, published 18 October 2026.

Which products and versions are affected?

Linux Kernel dm-pcache component; patched from commit 7ac1f10f987a2ffae4aecf0e2ceca8f552b665cb onwards.

Is there a fix for CVE-2026-98868?

A patch was published on 2026-09-14. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-98868 attacked?

It is attacked with local access, in an operating system.

Am I affected by CVE-2026-98868?

Check whether you run Linux Kernel at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-98868: Linux kernel dm-pcache buffer over-read in segment processing

CVE-2026-98868 · Severity: info · Published 2026-10-18

The Linux kernel's dm-pcache (persistent cache) component can be tricked into reading past the end of a memory segment when processing specially crafted cache key sets. A local attacker with the ability to forge cache metadata could trigger a kernel crash (denial of service) or potentially leak sensitive kernel memory.

Technologies: Linux Kernel. Vendors: Linux.

Quick answers

Is CVE-2026-98868 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-98868 being exploited in the wild.
How severe is CVE-2026-98868?: Informational severity, published 18 October 2026.
Which products and versions are affected?: Linux Kernel dm-pcache component; patched from commit 7ac1f10f987a2ffae4aecf0e2ceca8f552b665cb onwards.
Is there a fix for CVE-2026-98868?: A patch was published on 2026-09-14. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-98868 attacked?: It is attacked with local access, in an operating system.
Am I affected by CVE-2026-98868?: Check whether you run Linux Kernel at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability exists in the cache_replay(), writeback worker, and garbage collector functions in drivers/md/dm-pcache. A malformed key_num field in an on-media key set structure causes get_kset_onmedia_size() to return a value exceeding the remaining segment space, leading to an out-of-bounds read and a BUG_ON crash in cache_pos_advance(). The fix adds a bounds check comparing the calculated kset size against cache_seg_remain() before processing.

Affected products

Linux Linux kernel dm-pcache component; patched from commit 7ac1f10f987a2ffae4aecf0e2ceca8f552b665cb onwards

Timeline

2026-07-17: disclosed
2026-09-14: patched

References

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