CVE-2026-80733

net: remove WARN_ON_ONCE() from sk_mc_loop()

Published Sep 3, 2026 CVSS n/a EPSS < 1% KEV · Not listed

Description

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

net: remove WARN_ON_ONCE() from sk_mc_loop()

sk_mc_loop() can be called for sockets that are neither AF_INET
nor AF_INET6 (e.g. AF_PACKET sockets when sending packets via raw/packet
socket over virtual devices such as VRF or ipvlan).

In such cases, sk_family is not AF_INET/AF_INET6 and sk_mc_loop() falls
through the switch statement and triggers WARN_ON_ONCE(1).

Non-INET sockets do not support IP_MULTICAST_LOOP or IPV6_MULTICAST_LOOP
options, so loopback should default to true without generating a warning.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Linux

unaffected

Version	Status	Constraints
`f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90`	affected	< 97133c4d42654578fab95abe47359ebe784dde18
`f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90`	affected	< f625c742b33dc137c209dd13d1c5f12b1c18d71c
`f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90`	affected	< ad7fa2f411cb30f63d6725f111be134064cdb718
`f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90`	affected	< d2adc4e80b29e58b5162ae09f0f657a215806c8c
`f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90`	affected	< ad7dbb1d14b1b4406eca8ef9478e8de312ba0cfe
`f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90`	affected	< c8f256dc849205ccb2bd78bd99a3497b972b44e0
`f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90`	affected	< 0d75f2c1d0764efa756ad9c1e078d8c09ea8fc1f
`f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90`	affected	< b8a39a09ae4eaae04309e1e38ed6a1101d967496
`c91f81773cd4bbebfe744e9ab30a7ce093f9b930`	affected	—
`c8c30b2b17f2133e953850c547e3902c3a3d80e2`	affected	—
`3fe207e4637a2e792c46a08666aa722f77d7f8f7`	affected	—
`3.14.40`	affected	< 3.15
`3.18.13`	affected	< 3.19
`3.19.6`	affected	< 3.20

Linux

affected

Version	Status	Constraints
`4.0`	affected	—
`0`	unaffected	< 4.0
`5.10.265`	unaffected	≤ 5.10.*
`5.15.216`	unaffected	≤ 5.15.*
`6.1.183`	unaffected	≤ 6.1.*
`6.6.152`	unaffected	≤ 6.6.*
`6.12.104`	unaffected	≤ 6.12.*
`6.18.45`	unaffected	≤ 6.18.*
`7.1.9`	unaffected	≤ 7.1.*
`7.2`	unaffected	≤ *

No data.

Vendor Product Versions

Linux

Linux Kernel

Version	Status	Scheme	Platform
`[f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90,97133c4d42654578fab95abe47359ebe784dde18)`	affected	code_commit	—
`[f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90,f625c742b33dc137c209dd13d1c5f12b1c18d71c)`	affected	code_commit	—
`[f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90,ad7fa2f411cb30f63d6725f111be134064cdb718)`	affected	code_commit	—
`[f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90,d2adc4e80b29e58b5162ae09f0f657a215806c8c)`	affected	code_commit	—
`[f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90,ad7dbb1d14b1b4406eca8ef9478e8de312ba0cfe)`	affected	code_commit	—
`[f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90,c8f256dc849205ccb2bd78bd99a3497b972b44e0)`	affected	code_commit	—
`[f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90,0d75f2c1d0764efa756ad9c1e078d8c09ea8fc1f)`	affected	code_commit	—
`[f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90,b8a39a09ae4eaae04309e1e38ed6a1101d967496)`	affected	code_commit	—
`c91f81773cd4bbebfe744e9ab30a7ce093f9b930`	affected	code_commit	—
`c8c30b2b17f2133e953850c547e3902c3a3d80e2`	affected	code_commit	—
`3fe207e4637a2e792c46a08666aa722f77d7f8f7`	affected	code_commit	—
`[3.14.40,3.15)`	affected	semver	—
`[3.18.13,3.19)`	affected	semver	—
`[3.19.6,3.20)`	affected	semver	—

Linux

Linux Kernel

Version	Status	Scheme	Platform
`4.0`	affected	semver	—
`[0,4.0)`	unaffected	semver	—
`[5.10.265,5.11.0)`	unaffected	semver	—
`[5.15.216,5.16.0)`	unaffected	semver	—
`[6.1.183,6.2.0)`	unaffected	semver	—
`[6.6.152,6.7.0)`	unaffected	semver	—
`[6.12.104,6.13.0)`	unaffected	semver	—
`[7.1.9,7.2.0)`	unaffected	semver	—
`[7.2,*]`	unaffected	semver	—

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

Source	ID	Title
Debian DLA	DLA-4777-1	linux security update
Debian DLA	DLA-4788-1	linux-6.12 security update
Ubuntu USN	USN-8875-1	Linux kernel vulnerabilities
Ubuntu USN	USN-8877-1	Linux kernel (GCP) vulnerabilities
Ubuntu USN	USN-8878-1	Linux kernel (GCP) vulnerabilities
Ubuntu USN	USN-8879-1	Linux kernel (Oracle) vulnerabilities
Ubuntu USN	USN-8875-2	Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN	USN-9019-1	Linux kernel (Azure) vulnerabilities
Ubuntu USN	USN-9020-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9022-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9023-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9024-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9025-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9026-1	Linux kernel (Azure) vulnerabilities
Ubuntu USN	USN-9029-1	Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN	USN-9039-1	Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN	USN-9040-1	Linux kernel (Low Latency NVIDIA) vulnerabilities
Ubuntu USN	USN-9066-1	Linux kernel (HWE) vulnerabilities
Ubuntu USN	USN-9091-1	Linux kernel (NVIDIA Tegra) vulnerabilities

Metrics

No CVSS v4.0

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.177% probability within 30 days)

Exploitation none

Automatable no

Technical Impact partial

References

Link	Providers
https://git.kernel.org/stable/c/0d75f2c1d0764efa756ad9c1e078d8c09ea8fc1f
https://git.kernel.org/stable/c/97133c4d42654578fab95abe47359ebe784dde18
https://git.kernel.org/stable/c/ad7dbb1d14b1b4406eca8ef9478e8de312ba0cfe
https://git.kernel.org/stable/c/ad7fa2f411cb30f63d6725f111be134064cdb718
https://git.kernel.org/stable/c/b8a39a09ae4eaae04309e1e38ed6a1101d967496
https://git.kernel.org/stable/c/c8f256dc849205ccb2bd78bd99a3497b972b44e0
https://git.kernel.org/stable/c/d2adc4e80b29e58b5162ae09f0f657a215806c8c
https://git.kernel.org/stable/c/f625c742b33dc137c209dd13d1c5f12b1c18d71c

History

Nov 7, 2026 7:30 AM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Sep 3, 2026 12:45 PM Weaknesses updated View changes

Type	Values Removed	Values Added
Weaknesses		CWE-589

Sep 3, 2026 7:30 AM Description updated. Title updated. First appearance in the feed. Affected versions updated. Affected vendors updated. Added references View changes

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: net: remove WARN_ON_ONCE() from sk_mc_loop() sk_mc_loop() can be called for sockets that are neither AF_INET nor AF_INET6 (e.g. AF_PACKET sockets when sending packets via raw/packet socket over virtual devices such as VRF or ipvlan). In such cases, sk_family is not AF_INET/AF_INET6 and sk_mc_loop() falls through the switch statement and triggers WARN_ON_ONCE(1). Non-INET sockets do not support IP_MULTICAST_LOOP or IPV6_MULTICAST_LOOP options, so loopback should default to true without generating a warning.
Title		net: remove WARN_ON_ONCE() from sk_mc_loop()
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/0d75f2c1d0764efa756ad9c1e078d8c09ea8fc1f https://git.kernel.org/stable/c/97133c4d42654578fab95abe47359ebe784dde18 https://git.kernel.org/stable/c/ad7dbb1d14b1b4406eca8ef9478e8de312ba0cfe https://git.kernel.org/stable/c/ad7fa2f411cb30f63d6725f111be134064cdb718 https://git.kernel.org/stable/c/b8a39a09ae4eaae04309e1e38ed6a1101d967496 https://git.kernel.org/stable/c/c8f256dc849205ccb2bd78bd99a3497b972b44e0 https://git.kernel.org/stable/c/d2adc4e80b29e58b5162ae09f0f657a215806c8c https://git.kernel.org/stable/c/f625c742b33dc137c209dd13d1c5f12b1c18d71c