VulnerabilityPublished 8 May 2026Updated 21 Oct 2026

CVE-2026-43308: Linux kernel · btrfs: don't BUG() on unexpected delayed ref type in run_one_delayed_ref()

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in c7d1d4ff56744074e005771aff193b927392d51f : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:07 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS: 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in c7d1d4ff56744074e005771aff193b927392d51f, a5ac87aabdedd31e832b40466605e83f428136aa, 5549743e11c06da23cfa7712a994b9f1e69064c6 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 8 May 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 ≥ 5d4f98a28c7d334091c1b7744f48a1acdd2a4ae0, < c7d1d4ff56744074e005771aff193b927392d51f	Fixed in c7d1d4ff56744074e005771aff193b927392d51f
LinuxLinux	Affected ≥ 5d4f98a28c7d334091c1b7744f48a1acdd2a4ae0, < a5ac87aabdedd31e832b40466605e83f428136aa	Fixed in a5ac87aabdedd31e832b40466605e83f428136aa
LinuxLinux	Affected ≥ 5d4f98a28c7d334091c1b7744f48a1acdd2a4ae0, < 5549743e11c06da23cfa7712a994b9f1e69064c6	Fixed in 5549743e11c06da23cfa7712a994b9f1e69064c6
LinuxLinux	Affected ≥ 5d4f98a28c7d334091c1b7744f48a1acdd2a4ae0, < 6ad4caadc6343c3d7987bf3211f15d66135c4c42	Fixed in 6ad4caadc6343c3d7987bf3211f15d66135c4c42
LinuxLinux	Affected ≥ 5d4f98a28c7d334091c1b7744f48a1acdd2a4ae0, < 0e77f1c8ebf5b1f858b5ac613baceb79919d6d3f	Fixed in 0e77f1c8ebf5b1f858b5ac613baceb79919d6d3f
LinuxLinux	Affected =2.6.31	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: don't BUG() on unexpected delayed ref type in run_one_delayed_ref() There is no need to BUG(), we can just return an error and log an error message.

References

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