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VulnerabilityPublished Updated

CVE-2025-37839: Linux kernel · jbd2: remove wrong sb->s_sequence check

Source GCVE Database

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Authoritative record:CVE-2025-37839

Not known to be exploited · CVSS 7.8 High.

Data as of 13 Nov 2026, 18:57 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 9 May 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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 13 Nov 2026.

What to do

AI-suggested

A fix has been applied to the Linux kernel to remove the incorrect sb->s_sequence check. Users should update to the fixed kernel versions once available. Since this is a kernel-level issue, applying the official kernel patch or upgrading to a patched kernel release is the recommended mitigation.

Description

CVE-2025-37839 is a vulnerability in the Linux kernel's jbd2 journaling subsystem caused by an incorrect check of the superblock sequence number (sb->s_sequence). The vulnerability arises because the code incorrectly uses sb->s_sequence == 0 to determine journal emptiness, whereas the correct check should be sb->s_start == 0. Since 0 is a valid transaction ID, the faulty check can trigger spurious warnings. This issue has been resolved by removing the invalid check.

References

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