netfilter: xt_multiport: validate range encoding in checkentry
Summary
| CVE | CVE-2026-31681 |
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-25 09:16:01 UTC |
| Updated | 2026-04-25 09:16:01 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved:
netfilter: xt_multiport: validate range encoding in checkentry
ports_match_v1() treats any non-zero pflags entry as the start of a
port range and unconditionally consumes the next ports[] element as
the range end.
The checkentry path currently validates protocol, flags and count, but
it does not validate the range encoding itself. As a result, malformed
rules can mark the last slot as a range start or place two range starts
back to back, leaving ports_match_v1() to step past the last valid
ports[] element while interpreting the rule.
Reject malformed multiport v1 rules in checkentry by validating that
each range start has a following element and that the following element
is not itself marked as another range start. |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected a89ecb6a2ef732d04058d87801e2b6bd7e5c7089 aec14808271f2bf2b656de6ff12dfe73c5fd3b67 git |
Not specified |
| CNA |
Linux |
Linux |
affected a89ecb6a2ef732d04058d87801e2b6bd7e5c7089 8368ce8eb01f0b91111d814703696e780d0ef12f git |
Not specified |
| CNA |
Linux |
Linux |
affected a89ecb6a2ef732d04058d87801e2b6bd7e5c7089 1e4baa853f1cc4227e04f52d6860524707cfb294 git |
Not specified |
| CNA |
Linux |
Linux |
affected a89ecb6a2ef732d04058d87801e2b6bd7e5c7089 ff64c5bfef12461df8450e0f50bb693b5269c720 git |
Not specified |
| CNA |
Linux |
Linux |
affected 2.6.17 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 2.6.17 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.12.83 6.12.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.18.24 6.18.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.19.14 6.19.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.0 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/8368ce8eb01f0b91111d814703696e780d0ef12f |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/aec14808271f2bf2b656de6ff12dfe73c5fd3b67 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/1e4baa853f1cc4227e04f52d6860524707cfb294 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/ff64c5bfef12461df8450e0f50bb693b5269c720 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| CVE Program record |
CVE.ORG |
www.cve.org |
canonical |
| NVD vulnerability detail |
NVD |
nvd.nist.gov |
canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.