CVE-2026-72347

netfilter: xt_connmark: reject invalid shift parameters

State: Published
Severity: 7.3 High
Published: Aug 15, 2026
Updated: Oct 16, 2026
Reserved: Aug 9, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: xt_connmark: reject invalid shift parameters

Revision 2 of the CONNMARK target accepts user-controlled shift parameters and applies them to 32-bit mark values in connmark_tg_shift().

A shift_bits value of 32 or more triggers an undefined-shift bug when the rule is evaluated. Invalid shift_dir values are also accepted and silently fall back to the left-shift path.

Reject invalid revision-2 shift parameters in connmark_tg_check() so malformed rules fail at installation time, before they can reach the packet path.

Scores

CVSS	Score	Vector	Source
3.1	7.3 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	472a73e00757b971d613d796374d2727b2e4954d to before d8ce63d928b457fba7ed1e302492dfd32293671cAffected 472a73e00757b971d613d796374d2727b2e4954d to before 9657bb11a6376ab0a79f05d433713d6944111e9dAffected 472a73e00757b971d613d796374d2727b2e4954d to before 8ace320ac4416f5e5fbcd065309fb2dfcce787b0Affected 472a73e00757b971d613d796374d2727b2e4954d to before c3fa852d117b3fda72265e4230e3967db4a74fcfAffected 472a73e00757b971d613d796374d2727b2e4954d to before 4eef84b09a3836919360c4232b0f16651a155eecAffected 472a73e00757b971d613d796374d2727b2e4954d to before 230173cc6105bdfb2696d37e6e56687b003fbe63Affected 472a73e00757b971d613d796374d2727b2e4954d to before 1b47026fb4b35bac850ad6e8a4ad7fc018e09ebcAffected
LinuxLinux	4.17Affected before 4.17Not affected 5.15.212 through 5.15.Not affected 6.1.178 through 6.1.Not affected 6.6.145 through 6.6.Not affected 6.12.97 through 6.12.Not affected 6.18.40 through 6.18.Not affected 7.1.5 through 7.1.Not affected 7.2 and laterNot affected

Product

Versions

LinuxLinux

472a73e00757b971d613d796374d2727b2e4954d to before d8ce63d928b457fba7ed1e302492dfd32293671cAffected
472a73e00757b971d613d796374d2727b2e4954d to before 9657bb11a6376ab0a79f05d433713d6944111e9dAffected
472a73e00757b971d613d796374d2727b2e4954d to before 8ace320ac4416f5e5fbcd065309fb2dfcce787b0Affected
472a73e00757b971d613d796374d2727b2e4954d to before c3fa852d117b3fda72265e4230e3967db4a74fcfAffected
472a73e00757b971d613d796374d2727b2e4954d to before 4eef84b09a3836919360c4232b0f16651a155eecAffected
472a73e00757b971d613d796374d2727b2e4954d to before 230173cc6105bdfb2696d37e6e56687b003fbe63Affected
472a73e00757b971d613d796374d2727b2e4954d to before 1b47026fb4b35bac850ad6e8a4ad7fc018e09ebcAffected

LinuxLinux

4.17Affected
before 4.17Not affected
5.15.212 through 5.15.*Not affected
6.1.178 through 6.1.*Not affected
6.6.145 through 6.6.*Not affected
6.12.97 through 6.12.*Not affected
6.18.40 through 6.18.*Not affected
7.1.5 through 7.1.*Not affected
7.2 and laterNot affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.