CVE-2025-38477: Linux kernel · net/sched: sch_qfq: Fix race condition on qfq_aggregate
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 4.15.0-1193.208~14.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.15.0-1193.208~14.04.1, 4.15.0-1185.198~16.04.1, 4.15.0-1193.208~16.04.1 +103
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 28 Jul 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-7791-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7792-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7793-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7795-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7796-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7791-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7798-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7799-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7792-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7801-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7793-2 (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-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?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– |
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: net/sched: sch_qfq: Fix race condition on qfq_aggregate A race condition can occur when 'agg' is modified in qfq_change_agg (called during qfq_enqueue) while other threads access it concurrently. For example, qfq_dump_class may trigger a NULL dereference, and qfq_delete_class may cause a use-after-free. This patch addresses the issue by: 1. Moved qfq_destroy_class into the critical section. 2. Added sch_tree_lock protection to qfq_dump_class and qfq_dump_class_stats.
References
- ubuntu.com/security/CVE-2025-38477 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-38477 (opens in a new tab)
- git.kernel.org/linus/5e28d5a3f774f118896aec17a3a20a9c5c9dfc64 (opens in a new tab)
- git.kernel.org/stable/c/466e10194ab81caa2ee6a332d33ba16bcceeeba6 (opens in a new tab)
- git.kernel.org/stable/c/5e28d5a3f774f118896aec17a3a20a9c5c9dfc64 (opens in a new tab)
- git.kernel.org/stable/c/a6d735100f602c830c16d69fb6d780eebd8c9ae1 (opens in a new tab)
- git.kernel.org/stable/c/c000a3a330d97f6c073ace5aa5faf94b9adb4b79 (opens in a new tab)
- git.kernel.org/stable/c/fbe48f06e64134dfeafa89ad23387f66ebca3527 (opens in a new tab)
- ubuntu.com/security/notices/USN-7791-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7792-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7793-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7795-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7796-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7791-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7798-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7799-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7792-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7801-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7793-2 (opens in a new tab)