CVE-2025-37798 | codel: remove sch->q.qlen check before qdisc_tree_reduce_backlog()

In the Linux kernel, the following vulnerability has been resolved: codel: remove sch->q.qlen check before qdisc_tree_reduce_backlog() After making all ->qlen_notify() callbacks idempotent, now it is safe to remove the check of qlen!=0 from both fq_codel_dequeue() and codel_qdisc_dequeue().

Published: 2025-05-02 Last update: 2025-11-06 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-37798 is rated Low Risk (34.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.03%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-37798

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-10 0.08% 0.03% -0.05%
2 2026-02-26 0.02% 0.08% +0.06%
3 2025-11-07 — 0.02% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-37798

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]

Weakness enumeration for CVE-2025-37798

OS Trackers for CVE-2025-37798

vendor priority summary link
debian not yet assigned CVE-2025-37798 not yet assigned priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. https://security-tracker.debian.org/tracker/CVE-2025-37798
redhat medium — https://access.redhat.com/security/cve/CVE-2025-37798
suse high — https://www.suse.com/security/cve/CVE-2025-37798/
ubuntu medium CVE-2025-37798 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, released 220, ignored 148, not-affected 35, needs-triage 2, needed 1. https://ubuntu.com/security/CVE-2025-37798

Affected software / configurations for CVE-2025-37798

Vendor Product Version Raw CPE
linux linux_kernel >= 3.5, < 5.4.297 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.5, < 5.10.241 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.11, < 5.15.190 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.16, < 6.1.135 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.2, < 6.6.88 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.7, < 6.12.24 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.13, < 6.13.12 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.14, < 6.14.3 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 6.15 cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

References for CVE-2025-37798

URL Tags
https://git.kernel.org/stable/c/2f9761a94bae33d26e6a81b31b36e7d776d93dc1 Patch
https://git.kernel.org/stable/c/342debc12183b51773b3345ba267e9263bdfaaef Patch
https://git.kernel.org/stable/c/4d55144b12e742404bb3f8fee6038bafbf45619d Patch
https://git.kernel.org/stable/c/7a742a9506849d1c1aa71e36c89855ceddc7d58e Patch
https://git.kernel.org/stable/c/829c49b6b2ff45b043739168fd1245e4e1a91a30 Patch
https://git.kernel.org/stable/c/a57fe60ef4cf96bfbb6b58397ec28bdb5a5c6b31 Patch
https://git.kernel.org/stable/c/cc71a757da78dd4aa1b4a9b19cb011833730ccf2 Patch
https://git.kernel.org/stable/c/e73c838c80dccb9e4f19becc11d9f3cb4a27d483 Patch
https://git.kernel.org/stable/c/eda741fe155ddf5ecd2dd3bfbd4fc3c0c7dbb450 Patch
https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html Issue Tracking Third Party Advisory
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html Issue Tracking Third Party Advisory
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