7.5

CVE-2025-21646: linux

CVSS: 7.5v3.1HighModified
AliasesUBUNTU-CVE-2025-21646DEBIAN-CVE-2025-21646
Published 19-01-2025Last modified 05-08-2026
Open JSON

Vulnerability summary

CVE-2025-21646 is a high (CVSS 7.5) vulnerability in linux. EPSS estimates a 0.45% chance of exploitation in the next 30 days, higher than 37.6% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.45%
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 39 · Related 35
DLA-4075-1DLA-4076-1DSA-5860-1MGASA-2025-0030MGASA-2025-0032RHSA-2025:6966

Timeline

  1. 19-01-2025
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: afs: Fix the maximum cell name length The kafs filesystem limits the maximum length of a cell to 256 bytes, but a problem occurs if someone actually does that: kafs tries to create a directory under /proc/net/afs/ with the name of the cell, but that fails with a warning: WARNING: CPU: 0 PID: 9 at fs/proc/generic.c:405 because procfs limits the maximum filename length to 255. However, the DNS limits the maximum lookup length and, by extension, the maximum cell name, to 255 less two (length count and trailing NUL). Fix this by limiting the maximum acceptable cellname length to 253. This also allows us to be sure we can create the "/afs/.<cell>/" mountpoint too. Further, split the YFS VL record cell name maximum to be the 256 allowed by the protocol and ignore the record retrieved by YFSVL.GetCellName if it exceeds 253.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.45%

Chance of exploitation in the next 30 days

Percentile

38%

Versus all other CVEs

30-day change

0.00 pp

From 0.45% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.45%

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

Ubuntu123 products
  • linux< 5.15.0-135.146 | < 6.8.0-60.63
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 5.15.0-1080.87 | < 6.8.0-1029.31
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ c3e9f888263bb4df11cbd623ceced02081cb2f9f, < 9340385468d056bb700b8f28df236b81fc86a079 | ≥ c3e9f888263bb4df11cbd623ceced02081cb2f9f, < 7cb3e77e9b4e6ffa325a5559393d3283c9af3d01 | ≥ c3e9f888263bb4df11cbd623ceced02081cb2f9f, < aabe47cf5ac5e1db2ae0635f189d836f67024904 | ≥ c3e9f888263bb4df11cbd623ceced02081cb2f9f, < 7673030efe0f8ca1056d3849d61784c6caa052af | ≥ c3e9f888263bb4df11cbd623ceced02081cb2f9f, < 7922b1f058fe24a93730511dd0ae2e1630920096 | ≥ c3e9f888263bb4df11cbd623ceced02081cb2f9f, < 8fd56ad6e7c90ac2bddb0741c6b248c8c5d56ac8 | 5.8
  • linux_kernel≥ 5.8, < 5.10.234 | ≥ 5.11, < 5.15.177 | ≥ 5.16, < 6.1.125 | ≥ 6.2, < 6.6.72 | ≥ 6.7, < 6.12.10 | 6.13:rc1 | 6.13:rc2 | 6.13:rc3 | 6.13:rc4 | 6.13:rc5 | 6.13:rc6
Debian1 product
  • linux< 6.1.128-1 | < 6.12.10-1

3 vendors · 126 products

References

39 links
Show all 39 references