CVE-2025-21962: cifs: Fix integer overflow while processing closetimeo mount option
Vulnerability summary
CVE-2025-21962 is a medium (CVSS 5.5) Integer Overflow or Wraparound vulnerability in linux. EPSS estimates a 0.21% chance of exploitation in the next 30 days, higher than 10.8% of scored vulnerabilities.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 48 · Related 42Timeline
- 01-04-2025PublishedVulnerability first disclosed.
- 23-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: cifs: Fix integer overflow while processing closetimeo mount option User-provided mount parameter closetimeo of type u32 is intended to have an upper limit, but before it is validated, the value is converted from seconds to jiffies which can lead to an integer overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- NVDNIST5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.21%
Chance of exploitation in the next 30 days
Percentile
11%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.20% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu125 products
- linux< 5.15.0-142.152 | < 6.8.0-84.84
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 5.15.0-1086.93 | < 6.8.0-1039.41
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 1d9cad9c5873097ea141ffc5da1e7921ce765aa8, < 513f6cf2e906a504b7ab0b62b2eea993a6f64558 | ≥ 5efdd9122eff772eae2feae9f0fc0ec02d4846a3, < 9968fcf02cf6b0f78fbacf3f63e782162603855a | ≥ 5efdd9122eff772eae2feae9f0fc0ec02d4846a3, < 6c13fcb7cf59ae65940da1dfea80144e42921e53 | ≥ 5efdd9122eff772eae2feae9f0fc0ec02d4846a3, < 1c46673be93dd2954f44fe370fb4f2b8e6214224 | ≥ 5efdd9122eff772eae2feae9f0fc0ec02d4846a3, < b24edd5c191c2689c59d0509f0903f9487eb6317 | ≥ 5efdd9122eff772eae2feae9f0fc0ec02d4846a3, < d5a30fddfe2f2e540f6c43b59cf701809995faef | ≥ 5.15.107, < 5.15.180 | 6.0
- linux_kernel≥ 5.15.107, < 5.15.180 | ≥ 6.0, < 6.1.132 | ≥ 6.2, < 6.6.84 | ≥ 6.7, < 6.12.20 | ≥ 6.13, < 6.13.8 | 6.14:rc1 | 6.14:rc2 | 6.14:rc3 | 6.14:rc4 | 6.14:rc5 | 6.14:rc6
Debian1 product
- linux< 6.1.133-1 | < 6.12.20-1
3 vendors · 128 products
