CVE-2025-21836
Medium
Elevated severity or exploit probability.
CVSS base
7.8
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS — probability of exploitation (30 days)
0.2%
16.3th percentile
CISA KEV
Not listed
Weakness / dates
—
Published 2025-03-07 · modified 2026-07-30
CVSS breakdown
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
| Attack Vector | L | Local |
| Attack Complexity | L | Low |
| Privileges Required | L | Low |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | H | High |
| Availability | H | High |
Timeline
- 2025-03-07 — Published (NVD)
- 2026-07-30 — Last modified (NVD)
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.
Affected
References
- https://git.kernel.org/stable/c/146a185f6c05ee263db715f860620606303c4633
- https://git.kernel.org/stable/c/2a5febbef40ce968e295a7aeaa5d5cbd9e3e5ad4
- https://git.kernel.org/stable/c/7d0dc28dae836caf7645fef62a10befc624dd17b
- https://git.kernel.org/stable/c/8802766324e1f5d414a81ac43365c20142e85603
- https://u1f383.github.io/slides/talks/2025_Hexacon-Deja_Vu_in_Linux_io_uring_Breaking_Memory_Sharing_Again_After_Generations_of_Fixes.pdf