CVE-2025-37915: Linux kernel · net_sched: drr: Fix double list add in class with netem as child qdisc
Source GCVE Database
Not known to be exploited · CVSS 7.0 High.
Data as of 13 Nov 2026, 19:33 UTC
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 20 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 patch has been applied to the Linux kernel to fix this issue by adding a check to prevent double addition of classes to the active list. Users should update to the fixed kernel versions once available. Since this is not a cloud service, manual patching is required. Patch status is not explicitly confirmed in the input, so users should consult the official Linux kernel advisories for the fixed versions and apply updates accordingly.
Description
A vulnerability in the Linux kernel's network scheduler (net_sched) involving the Deficit Round Robin (drr) queuing discipline was fixed. The issue caused a double addition of the same classifier to a list when netem was used as a child qdisc, leading to memory corruption. This was due to a reentrant enqueue callback in the parent qdisc. The patch adds a check to prevent adding a class twice to the active list.
References
- nvd.nist.gov/vuln/detail/CVE-2025-37915 (opens in a new tab)
- git.kernel.org/stable/c/26e75716b94d6ff9be5ea07d63675c4d189f30b4 (opens in a new tab)
- git.kernel.org/stable/c/2968632880f1792007eedd12eeedf7f6e2b7e9f3 (opens in a new tab)
- git.kernel.org/stable/c/4b07ac06b0a712923255aaf2691637693fc7100d (opens in a new tab)
- git.kernel.org/stable/c/4f0ecf50cdf76da95828578a92f130b653ac2fcf (opens in a new tab)
- git.kernel.org/stable/c/5da3aad1a13e7edb8ff0778a444ccf49930313e9 (opens in a new tab)
- git.kernel.org/stable/c/ab2248110738d4429668140ad22f530a9ee730e1 (opens in a new tab)
- git.kernel.org/stable/c/db205b92dfe0501e5b92fb7cf00971d0e44ba3eb (opens in a new tab)
- git.kernel.org/stable/c/f99a3fbf023e20b626be4b0f042463d598050c9a (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/08/msg00010.html (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/10/msg00007.html (opens in a new tab)