CVE-2026-80733
net: remove WARN_ON_ONCE() from sk_mc_loop()
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.
INFO
Published Date :
Sept. 3, 2026, 1:06 p.m.
Last Modified :
Sept. 3, 2026, 1:06 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel.
- Ensure non-INET sockets default loopback to true.
- Verify WARN_ON_ONCE() is removed from sk_mc_loop().
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-80733.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-80733 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-80733
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-80733 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-80733 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 03, 2026
Action Type Old Value New Value 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/80xxx/CVE-2026-80733.json">CVE-2026-80733</a> Added Reference https://git.kernel.org/stable/c/0d75f2c1d0764efa756ad9c1e078d8c09ea8fc1f Added Reference https://git.kernel.org/stable/c/97133c4d42654578fab95abe47359ebe784dde18 Added Reference https://git.kernel.org/stable/c/ad7dbb1d14b1b4406eca8ef9478e8de312ba0cfe Added Reference https://git.kernel.org/stable/c/ad7fa2f411cb30f63d6725f111be134064cdb718 Added Reference https://git.kernel.org/stable/c/b8a39a09ae4eaae04309e1e38ed6a1101d967496 Added Reference https://git.kernel.org/stable/c/c8f256dc849205ccb2bd78bd99a3497b972b44e0 Added Reference https://git.kernel.org/stable/c/d2adc4e80b29e58b5162ae09f0f657a215806c8c Added Reference https://git.kernel.org/stable/c/f625c742b33dc137c209dd13d1c5f12b1c18d71c