CVE-2025-37839: Linux kernel · jbd2: remove wrong sb->s_sequence check
Source GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 13 Nov 2026, 18:57 UTC
Thin evidence
One scorer or noneCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 9 May 2025
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 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
- nvd.nist.gov/vuln/detail/CVE-2025-37839 (opens in a new tab)
- git.kernel.org/stable/c/3b4643ffaf72d7a5a357e9bf68b1775f8cfe7e77 (opens in a new tab)
- git.kernel.org/stable/c/9eaec071f111cd2124ce9a5b93536d3f6837d457 (opens in a new tab)
- git.kernel.org/stable/c/ad926f735b4d4f10768fec7d080cadeb6d075cac (opens in a new tab)
- git.kernel.org/stable/c/b0cca357f85beb6144ab60c62dcc98508cc044bf (opens in a new tab)
- git.kernel.org/stable/c/b479839525fe7906966cdc4b5b2afbca048558a1 (opens in a new tab)
- git.kernel.org/stable/c/c88f7328bb0fff66520fc9164f02b1d06e083c1b (opens in a new tab)
- git.kernel.org/stable/c/c98eb9ffb1d9c98237b5e1668eee17654e129fb0 (opens in a new tab)
- git.kernel.org/stable/c/cf30432f5b3064ff85d85639c2f0106f89c566f6 (opens in a new tab)
- git.kernel.org/stable/c/e6eff39dd0fe4190c6146069cc16d160e71d1148 (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/05/msg00030.html (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/05/msg00045.html (opens in a new tab)