Linux Distros Unpatched Vulnerability : CVE-2026-99285

critical Nessus Plugin ID 378551

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

- netfilter: nft_byteorder: remove multi-register support 64bit byteorder conversion is broken when several registers need to be converted because the source register array advances in steps for 4 bytes instead of 8: for (i = ... src64 = nft_reg_load64(&src[i]); ~~~~~ u32 *src nft_reg_store64(&dst64[i], Remove the multi-register support, it has other issues as well: Pablo points out that commit caf3ef7468f7 (netfilter: nf_tables: prevent OOB access in nft_byteorder_eval) alters semantics: before the loop operated on registers, i.e. for ( ... ) dst32[i] = htons((u16)src32[i]) .. but after the patch it will operate on bytes, which makes this useless to convert e.g. concatenations, which store each compound in its own register. Multi-convert of u32 has one theoretical application: ct mark . meta mark . tcp dport @intervalset Because ct mark and meta mark are host byte order, use with intervals has to convert the byteorder for ct/meta mark value to network byte order (bigendian). nftables emits this: [ meta load mark => reg 1 ] [ byteorder reg 1 = hton(reg 1, 4, 4) ] [ ct load mark => reg 9 ] [ byteorder reg 9 = hton(reg 9, 4, 4) ] ... I.e. two separate calls. Theoretically it could be changed to do: [ meta load mark => reg 1 ] [ ct load mark => reg 9 ] [ byteorder reg 1 = htonl(reg 1, 4, 8) ] ... But then all it would take to change the set to meta mark . tcp dport . ct mark ... and we'd be back to two byteorder calls. IOW, support to convert a range of registers is both dysfunctional and dubious. Simplify this: remove the feature. Pablo Neira Ayuso points out that nftables before 1.1.0 can generate incorrect byteorder conversions, see 9fe58952c45a, evaluate: skip byteorder conversion for selector smaller than 2 bytes in nftables.git). Affected rulesets fail to load with this change and old userspace due to 'len != size' check. (CVE-2026-99285)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

Plugin Details

Severity: Critical

ID: 378551

File Name: unpatched_CVE_2026_99285.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Misc.

Published: 11/10/2026

Updated: 11/10/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 2.1

Percentile: 8.41

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS Score Source: CVE-2026-99285

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:U/RC:C

Vulnerability Information

CPE: cpe:/o:debian:debian_linux:12.0, p-cpe:/a:debian:debian_linux:linux

Required KB Items: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 11/10/2026

Reference Information

CVE: CVE-2026-99285

Detections

Analytics