CVE-2025-21646afs: Fix the maximum cell name length
- 7.5HighCVSS base score
- 0.45%Exploitation in 30 daysEPSS · top 60% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By Linux
- 21 days later
· 21 days later
Published
- 19 months later
· 19 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.45% · top 60% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
- affected c3e9f888263bb4df11cbd623ceced02081cb2f9f – < 9340385468d056bb700b8f28df236b81fc86a079
- affected c3e9f888263bb4df11cbd623ceced02081cb2f9f – < 7cb3e77e9b4e6ffa325a5559393d3283c9af3d01
- affected c3e9f888263bb4df11cbd623ceced02081cb2f9f – < aabe47cf5ac5e1db2ae0635f189d836f67024904
- affected c3e9f888263bb4df11cbd623ceced02081cb2f9f – < 7673030efe0f8ca1056d3849d61784c6caa052af
- affected c3e9f888263bb4df11cbd623ceced02081cb2f9f – < 7922b1f058fe24a93730511dd0ae2e1630920096
- affected c3e9f888263bb4df11cbd623ceced02081cb2f9f – < 8fd56ad6e7c90ac2bddb0741c6b248c8c5d56ac8
- affected 5.8
- unaffected < 5.8
- unaffected 5.10.234 – ≤ 5.10.*
- unaffected 5.15.177 – ≤ 5.15.*
- unaffected 6.1.125 – ≤ 6.1.*
- unaffected 6.6.72 – ≤ 6.6.*
- unaffected 6.12.10 – ≤ 6.12.*
- unaffected 6.13 – ≤ *
References
References8
- https://git.kernel.org/stable/c/9340385468d056bb700b8f28df236b81fc86a079 (opens in a new tab)
- https://git.kernel.org/stable/c/7cb3e77e9b4e6ffa325a5559393d3283c9af3d01 (opens in a new tab)
- https://git.kernel.org/stable/c/aabe47cf5ac5e1db2ae0635f189d836f67024904 (opens in a new tab)
- https://git.kernel.org/stable/c/7673030efe0f8ca1056d3849d61784c6caa052af (opens in a new tab)
- https://git.kernel.org/stable/c/7922b1f058fe24a93730511dd0ae2e1630920096 (opens in a new tab)
- https://git.kernel.org/stable/c/8fd56ad6e7c90ac2bddb0741c6b248c8c5d56ac8 (opens in a new tab)
- https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html (opens in a new tab)
- https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-2595 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-21646)Record last updated .