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Review reviewCritical

CVE-2026-31402

Linux Linux, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix heap overflow in NFSv4.0 LOCK replay cache The NFSv4.0 replay cache uses a fixed 112-byte inline buffer (rp_ibuf[NFSD4_REPLAY_ISIZE]) to store encoded operation responses. This size was calculated based on OPEN responses and does not account for LOCK denied responses, which include the conflicting lock owner as a variable-length field up to 1024 bytes (NFS4_OPAQUE_LIMIT). When a LOCK operation is denied due to a conflict with an existing lock that has a large owner, nfsd4_encode_operation() copies the full encoded...

CVSS
9.8
EPSS
0.49%
39.5% percentile
CISA KEV
Not listed
Published
2026.04.04
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.49%
Technical severityCVSS 9.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix heap overflow in NFSv4.0 LOCK replay cache The NFSv4.0 replay cache uses a fixed 112-byte inline buffer (rp_ibuf[NFSD4_REPLAY_ISIZE]) to store encoded operation responses. This size was calculated based on OPEN responses and does not account for LOCK denied responses, which include the conflicting lock owner as a variable-length field up to 1024 bytes (NFS4_OPAQUE_LIMIT). When a LOCK operation is denied due to a conflict with an existing lock that has a large owner, nfsd4_encode_operation() copies the full encoded...

Affected product and versions

Product
Linux Linux, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support
Affected versions
>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < f9fcb4441f6c02bb20c2eb340101e27dfe23607c, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 2665887a69437a8a4f552f69509eecfb73d4aa19, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < c9452c0797c95cf2378170df96cf4f4b3bca7eff, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 8afb437ea1f70cacb4bbdf11771fb5c4d720b965, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < dad0c3c0a8e5d1d6eb0fc455694ce3e25e6c57d0, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 0f0e2a54a31a7f9ad2915db99156114872317388, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < ae8498337dfdfda71bdd0b807c9a23a126011d76, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 5133b61aaf437e5f25b1b396b14242a6bb0508e2, >= 2.6.12, >= V3.1.6, >= V3.1.5, >= 2.6.12.1 < 5.10.253, >= 5.11 < 6.1.167, >= 6.2 < 6.6.130, >= 6.7 < 6.12.78, >= 6.13 < 6.18.20, >= 6.19 < 6.19.10, 2.6.12, 7.0
Fixed versions
5.10.253, 6.1.167, 6.6.130, 6.12.78, 6.18.20, 6.19.10

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux Linux, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-787