CVE-2025-37839: Linux kernel · jbd2: remove wrong sb->s_sequence check
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1088.95~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 26% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1088.95~20.04.1, 5.15.0-1094.103~20.04.1, 5.15.0-1087.96~20.04.2 +58
CVSS: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
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.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7594-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7655-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7686-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7711-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7712-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: jbd2: remove wrong sb->s_sequence check Journal emptiness is not determined by sb->s_sequence == 0 but rather by sb->s_start == 0 (which is set a few lines above). Furthermore 0 is a valid transaction ID so the check can spuriously trigger. Remove the invalid WARN_ON.
References
- ubuntu.com/security/CVE-2025-37839 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-37839 (opens in a new tab)
- git.kernel.org/linus/e6eff39dd0fe4190c6146069cc16d160e71d1148 (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)
- ubuntu.com/security/notices/USN-7594-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7655-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-4 (opens in a new tab)