Review reviewHigh

CVE-2025-40204

Linux

In the Linux kernel, the following vulnerability has been resolved: sctp: Fix MAC comparison to be constant-time To prevent timing attacks, MACs need to be compared in constant time. Use the appropriate helper function for this.

CVSS: 8.1
EPSS: -
CISA KEV: Not listed
Published: 2025.11.13

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability-

Technical severityCVSS 8.1

Vulnerability overview

Affected product and versions

Product: Linux
Affected versions: >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < b93fa8dc521d00d2d44bf034fb90e0d79b036617, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 0e8b8c326c2a6de4d837b1bb034ea704f4690d77, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1cd60e0d0fb8f0e62ec4499138afce6342dc9d4c, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 9c05d44ec24126fc283835b68f82dba3ae985209, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < ed3044b9c810c5c24eb2830053fbfe5fd134c5d4, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 8019b3699289fce3f10b63f98601db97b8d105b0, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 0b32ff285ff6f6f1ac1d9495787ccce8837d6405, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < dd91c79e4f58fbe2898dac84858033700e0e99fb, >= 2.6.12
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that Linux and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE: Not available