CVE-2026-72347

netfilter: xt_connmark: reject invalid shift parameters

HIGH
7.3
CVSS Score
Published: August 15, 2026 at 05:55 AM UTC
Updated: October 16, 2026 at 07:17 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.3
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.17472a73e00757b971d613d796374d2727b2e4954d
Vendor states this is fixed in 1b47026fb4b35bac850ad6e8a4ad7fc018e09ebc (fixed)
Vendor states this is fixed in 230173cc6105bdfb2696d37e6e56687b003fbe63 (fixed)
Vendor states this is fixed in 4eef84b09a3836919360c4232b0f16651a155eec (fixed)
Vendor states this is fixed in 8ace320ac4416f5e5fbcd065309fb2dfcce787b0 (fixed)
Vendor states this is fixed in 9657bb11a6376ab0a79f05d433713d6944111e9d (fixed)
Vendor states this is fixed in c3fa852d117b3fda72265e4230e3967db4a74fcf (fixed)
Vendor states this is fixed in d8ce63d928b457fba7ed1e302492dfd32293671c (fixed)
Vendor states this is fixed in 4.17 (unaffected)
Vendor states this is fixed in 5.15.212 (unaffected)
Vendor states this is fixed in 6.1.178 (unaffected)
Vendor states this is fixed in 6.12.97 (unaffected)
Vendor states this is fixed in 6.18.40 (unaffected)
Vendor states this is fixed in 6.6.145 (unaffected)
Vendor states this is fixed in 7.1.5 (unaffected)
Vendor states this is fixed in 7.2 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.3HIGHLinux
Vector?

Quick Info

StatusRECEIVED

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