PT-2026-30185 · Linux+1 · Linux Kernel+1
Published
2026-02-24
·
Updated
2026-05-05
·
CVE-2026-31402
CVSS v3.1
9.8
Critical
| Vector | AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Name of the Vulnerable Software and Affected Versions
Linux kernel (affected versions not specified)
Description
The Linux kernel’s Network File System daemon (nfsd) contained a heap overflow in the NFSv4.0 LOCK replay cache. The NFSv4.0 replay cache uses a fixed 112-byte inline buffer to store encoded operation responses. This size was insufficient for LOCK denied responses, which can include a variable-length lock owner field up to 1024 bytes. When a LOCK operation is denied due to a conflict with an existing lock that has a large owner, the encoded response is copied into the undersized replay buffer without bounds checking, leading to a heap overflow of up to 944 bytes. This issue can be triggered remotely by an unauthenticated attacker using two cooperating NFSv4.0 clients. One client sets a lock with a large owner string, and the other requests a conflicting lock to provoke the denial.
Recommendations
At the moment, there is no information about a newer version that contains a fix for this vulnerability.
Exploit
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Weakness Enumeration
Related Identifiers
Affected Products
Linux Kernel
Rocky Linux