7.8

CVE-2025-21836: linux

CVSS: 7.8v3.1HighModified
AliasesUBUNTU-CVE-2025-21836DEBIAN-CVE-2025-21836
Published 07-03-2025Last modified 15-10-2026
Open JSON

Vulnerability summary

CVE-2025-21836 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 15.6% 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
0.25%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 18 · Related 19
SUSE-SU-2025:01614-1SUSE-SU-2025:01707-1SUSE-SU-2025:01919-1SUSE-SU-2025:01951-1SUSE-SU-2025:01964-1SUSE-SU-2025:01967-1

Timeline

  1. 07-03-2025
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: io_uring/kbuf: reallocate buf lists on upgrade IORING_REGISTER_PBUF_RING can reuse an old struct io_buffer_list if it was created for legacy selected buffer and has been emptied. It violates the requirement that most of the field should stay stable after publish. Always reallocate it instead.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.25%

Chance of exploitation in the next 30 days

Percentile

16%

Versus all other CVEs

30-day change

+0.01 pp

From 0.25% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.25%

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

Ubuntu107 products
  • linux< 6.8.0-78.78
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 6.8.0-1035.37
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 2fcabce2d7d34f69a888146dab15b36a917f09d4, < 146a185f6c05ee263db715f860620606303c4633 | ≥ 2fcabce2d7d34f69a888146dab15b36a917f09d4, < 7d0dc28dae836caf7645fef62a10befc624dd17b | ≥ 2fcabce2d7d34f69a888146dab15b36a917f09d4, < 2a5febbef40ce968e295a7aeaa5d5cbd9e3e5ad4 | ≥ 2fcabce2d7d34f69a888146dab15b36a917f09d4, < 8802766324e1f5d414a81ac43365c20142e85603 | 5.19
  • linux_kernel≥ 5.19, < 6.6.79 | ≥ 6.7, < 6.12.16 | ≥ 6.13, < 6.13.4 | 6.14:rc1 | 6.14:rc2
Debian1 product
  • linuxAll versions (No fix recorded) | < 6.12.16-1

3 vendors · 110 products

References

18 links
Show all 18 references