7.8

CVE-2025-40297: linux

CVSS: 7.8v3.1HighDeferred
AliasesUBUNTU-CVE-2025-40297DEBIAN-CVE-2025-40297
Published 08-12-2025Last modified 15-10-2026
Open JSON

Vulnerability summary

CVE-2025-40297 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 4.4% of scored vulnerabilities.

Overall risk
31/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.16%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 106 · Related 103
DLA-4436-1MGASA-2026-0017MGASA-2026-0018OPENSUSE-SU-2026:20145-1SUSE-SU-2026:0278-1SUSE-SU-2026:0281-1

Showing 100 of 106. Use Open JSON for the complete list.

Timeline

  1. 08-12-2025
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: net: bridge: fix use-after-free due to MST port state bypass syzbot reported[1] a use-after-free when deleting an expired fdb. It is due to a race condition between learning still happening and a port being deleted, after all its fdbs have been flushed. The port's state has been toggled to disabled so no learning should happen at that time, but if we have MST enabled, it will bypass the port's state, that together with VLAN filtering disabled can lead to fdb learning at a time when it shouldn't happen while the port is being deleted. VLAN filtering must be disabled because we flush the port VLANs when it's being deleted which will stop learning. This fix adds a check for the port's vlan group which is initialized to NULL when the port is getting deleted, that avoids the port state bypass. When MST is enabled there would be a minimal new overhead in the fast-path because the port's vlan group pointer is cache-hot. [1] https://syzkaller.appspot.com/bug?extid=dd280197f0f7ab3917be

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.16%

Chance of exploitation in the next 30 days

Percentile

4%

Versus all other CVEs

30-day change

0.00 pp

From 0.16% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.16%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Ubuntu127 products
  • linux< 6.8.0-100.100 | < 6.17.0-14.14
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 6.8.0-1046.49 | < 6.17.0-1007.7
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.1.159-1 | < 6.12.63-1 | < 6.17.8-1
Linux1 product
  • linux≥ ec7328b59176227216c461601c6bd0e922232a9b, < e19085b2a86addccff33ab8536fc67ebd9d52198 | ≥ ec7328b59176227216c461601c6bd0e922232a9b, < 3b60ce334c1ce8b3fad7e02dcd5ed9f6646477c8 | ≥ ec7328b59176227216c461601c6bd0e922232a9b, < bf3843183bc3158e5821b46f330c438ae9bd6ddb | ≥ ec7328b59176227216c461601c6bd0e922232a9b, < 991fbe1680cd41a5f97c92cd3a3496315df36e4b | ≥ ec7328b59176227216c461601c6bd0e922232a9b, < 8dca36978aa80bab9d4da130c211db75c9e00048 | 5.18

3 vendors · 129 products

References

31 links
Show all 31 references