VulnerabilityPublished 15 Aug 2026Updated 30 Oct 2026

CVE-2026-74308: Linux kernel · ext4: fix kernel BUG in ext4_write_inline_data_end

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in f00f5c0dd55319bc33b76f72c853bda0e0a32eda : update Linux kernel when convenient.

Data as of 30 Oct 2026, 13:20 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

Patch: Available – fixed in f00f5c0dd55319bc33b76f72c853bda0e0a32eda, ad09aa45965d3fafaf9963bc78109b73c0f9ac8d, 260830a9a706f5d335398236fc788ce32f220de1 +3

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 30 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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 ≥ 3fdcfb668fd78ec92d9bc2daddf1d41e2a8a30bb, < f00f5c0dd55319bc33b76f72c853bda0e0a32eda	Fixed in f00f5c0dd55319bc33b76f72c853bda0e0a32eda
LinuxLinux	Affected ≥ 3fdcfb668fd78ec92d9bc2daddf1d41e2a8a30bb, < ad09aa45965d3fafaf9963bc78109b73c0f9ac8d	Fixed in ad09aa45965d3fafaf9963bc78109b73c0f9ac8d
LinuxLinux	Affected ≥ 3fdcfb668fd78ec92d9bc2daddf1d41e2a8a30bb, < 260830a9a706f5d335398236fc788ce32f220de1	Fixed in 260830a9a706f5d335398236fc788ce32f220de1
LinuxLinux	Affected ≥ 3fdcfb668fd78ec92d9bc2daddf1d41e2a8a30bb, < 9808ae9fae996afa942bd963a39c9b1cdeebd0bd	Fixed in 9808ae9fae996afa942bd963a39c9b1cdeebd0bd
LinuxLinux	Affected ≥ 3fdcfb668fd78ec92d9bc2daddf1d41e2a8a30bb, < 13db1ccae4d38f6d9296ee74aa1d39b429959ddb	Fixed in 13db1ccae4d38f6d9296ee74aa1d39b429959ddb
LinuxLinux	Affected ≥ 3fdcfb668fd78ec92d9bc2daddf1d41e2a8a30bb, < 0ae42b51607240990614e0843f0d3529aaff62cc	Fixed in 0ae42b51607240990614e0843f0d3529aaff62cc

AI-suggested

A fix is available and has been applied in the Linux kernel source as indicated by multiple fixed commit versions. Users should update their Linux kernel to a version including these fixes to prevent the kernel BUG. No additional mitigation is required beyond applying the official patch.

Description

A kernel bug in the Linux ext4 filesystem was fixed related to the handling of inline data when the data=journal mount option is used. The ext4_journalled_write_end() function could incorrectly call ext4_write_inline_data_end() without verifying a necessary flag, leading to a kernel BUG triggered by an out-of-bounds write attempt. This occurs if a prior conversion of inline data to an extent failed, causing inconsistent inode flags. The fix ensures the function only proceeds if the appropriate flag is set, preventing the kernel BUG.

Impact

This vulnerability can cause a kernel BUG (crash) in the ext4 filesystem when using the data=journal mount option under specific conditions involving inline data conversion failures. This could lead to system instability or denial of service due to kernel panic. There is no indication of code execution or data corruption beyond the kernel crash.

Summary

CVE-2026-74308 addresses a kernel BUG in the Linux ext4 filesystem's ext4_write_inline_data_end function. When mounted with the data=journal option, ext4_journalled_write_end() improperly calls ext4_write_inline_data_end() without checking if the EXT4_STATE_MAY_INLINE_DATA flag remains set on the inode. If a previous inline data conversion failed and cleared this flag but left EXT4_INODE_INLINE_DATA set, ext4_journalled_write_end() attempts to write inline data without proper preparation, triggering a BUG_ON due to exceeding the inline data size. The patch adds a check to call ext4_write_inline_data_end() only if the EXT4_STATE_MAY_INLINE_DATA flag is set, aligning with other write end functions and preventing the kernel BUG.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Oct 2026, 13:20 UTC

Technical details

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