VulnerabilityPublished 6 Oct 2026Updated 21 Oct 2026

CVE-2026-98245: Linux kernel · btrfs: take commit root semaphore when iterating in mark_block_group_to_copy()

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in c32490c6d3f3a9f2d177d57c7eb8bbc347561d08 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:07 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in c32490c6d3f3a9f2d177d57c7eb8bbc347561d08, 709f6a5e986535005110c6c69b322f63631cb200, 0594e3423f4ba3137c734371169491f9a98e9af4 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 78ce9fc269af6e69c1399ab910ba6bc81c934f67, < c32490c6d3f3a9f2d177d57c7eb8bbc347561d08	Fixed in c32490c6d3f3a9f2d177d57c7eb8bbc347561d08
LinuxLinux	Affected ≥ 78ce9fc269af6e69c1399ab910ba6bc81c934f67, < 709f6a5e986535005110c6c69b322f63631cb200	Fixed in 709f6a5e986535005110c6c69b322f63631cb200
LinuxLinux	Affected ≥ 78ce9fc269af6e69c1399ab910ba6bc81c934f67, < 0594e3423f4ba3137c734371169491f9a98e9af4	Fixed in 0594e3423f4ba3137c734371169491f9a98e9af4
LinuxLinux	Affected ≥ 78ce9fc269af6e69c1399ab910ba6bc81c934f67, < 93a025166495c63ba5b8ac721c7040d5312e8335	Fixed in 93a025166495c63ba5b8ac721c7040d5312e8335
LinuxLinux	Affected ≥ 78ce9fc269af6e69c1399ab910ba6bc81c934f67, < 8e2007b263ea250251ec3021a0a197da990ee1a8	Fixed in 8e2007b263ea250251ec3021a0a197da990ee1a8
LinuxLinux	Affected =5.12	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: take commit root semaphore when iterating in mark_block_group_to_copy() mark_block_group_to_copy() iterates over the commit root with skip_locking=true. A concurrent transaction commit can swap and free the commit root during iteration, causing use-after-free when accessing extent buffers. Fix it by using path->need_commit_sem to protect the commit root search.

References

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