IM
IronMonkey Threat Research

CVE-2026-31681 MEDIUM

Published: 2026-04-25 | Last Modified: 2026-09-08 | Status: Modified

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.

CVSS Metrics

Base Score: 5.5 (MEDIUM)

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

Attack VectorLOCAL
Attack ComplexityLOW
Privileges RequiredLOW
User InteractionNONE
ScopeUNCHANGED
Confidentiality ImpactNONE
Integrity ImpactNONE
Availability ImpactHIGH

Source: [email protected]

Type: Primary

Exploitability Score: 1.8

Impact Score: 3.6

Weaknesses

Source Type Description
[email protected] Primary
en NVD-CWE-noinfo

Affected Products

Vendor Product Version Update Type
linux linux_kernel * <built-in method update of dict object at 0x7d239fbdd800> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7d23beb16480> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7d2357cce000> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7d239fbdf880> Operating System
linux linux_kernel 7.0 <built-in method update of dict object at 0x7d239fbde1c0> Operating System
linux linux_kernel 7.0 <built-in method update of dict object at 0x7d239fbdc380> Operating System
linux linux_kernel 7.0 <built-in method update of dict object at 0x7d23beb16100> Operating System
linux linux_kernel 7.0 <built-in method update of dict object at 0x7d239fbded80> Operating System
linux linux_kernel 7.0 <built-in method update of dict object at 0x7d239fbdcb80> Operating System
linux linux_kernel 7.0 <built-in method update of dict object at 0x7d239fbdc500> Operating System
linux linux_kernel 7.0 <built-in method update of dict object at 0x7d23a532d5c0> Operating System

Affected Configurations

Operator: OR

Vulnerable CPE
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*
Notification
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