CVE Intelligence
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CVE-2026-80996 — net: l2tp: do not propagate multicast notification errors

In the Linux kernel, the following vulnerability has been resolved: net: l2tp: do not propagate multicast notification errors The tunnel create, tunnel modify, session create, and session modify netlink handlers send multicast notifications through helpers that can fail while allocating or encoding a message, or while multicasting it. For tunnel and session create/modify, a notification is sent after the live operation has completed. Returning a best-effort notification error as the command result can therefore report failure for an operation that already committed and can cause callers to retry and accumulate live objects. Keep sending notifications for listener visibility, but do not propagate their best-effort status as the command result. This also keeps the tunnel modify command consistent with the other notification-only paths.

Published Sep 11, 2026 · Updated Oct 21, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.2% (30-day exploitation probability)+1

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.17%
ahead of 6% of scored CVEs · Oct 23, 2026
Affects
Linux
Linux
CVSS base
—
Score not published yet.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Linux Linux ≥ 33f72e6f0c67f673fd0c63a8182dbd9ffb8cf50b and < 0fe037d5eaad938aa3e9143ee071aa237750b42b≥ 33f72e6f0c67f673fd0c63a8182dbd9ffb8cf50b and < 9c340473f4822bb31b151c19afd17448eda5acd1≥ 33f72e6f0c67f673fd0c63a8182dbd9ffb8cf50b and < 50c4038f1670bf9a80c6a58ae83d1602decd8481≥ 33f72e6f0c67f673fd0c63a8182dbd9ffb8cf50b and < af20e269f7459d2ce69887fdf2fad7caf986c865version 4.0≥ 33f72e6f0c67f673fd0c63a8182dbd9ffb8cf50b and < 7efe1c31e0903a5aa796feb96d3adab574b7ff41 Vulnerable CVE Program (cve.org) e CISA ADP

EPSS over time FIRST

Oct 15, 2026 → Oct 23, 2026 · 8 reading(s) · max 0.17%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Not enough vector or weakness data: use the affected application’s logs as a starting point.
application logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · linux/linux
    Oct 21, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • Affected products added · linux/linux
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · → Received
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Sep 11, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 19, 2026 – Oct 21, 2026
  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

7 on the record

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

  • CVE-2026-99086 dm-integrity: validate the superblock on resume 1d
  • CVE-2026-99087 dm-integrity: fix NULL pointer dereference when the 'R' flag is used 1d
  • CVE-2026-99080 fs: Free any excess xarray nodes in clear_inode() 1d
  • CVE-2026-99084 readdir: take no inode lock on an immutable directory 1d
  • CVE-2026-99085 sched_ext: Fix CPU hotplug hang when a dying CPU's tasks sit in the BPF scheduler 1d
  • CVE-2026-99079 net/mlx5e: Prevent stale XSK buffer release on refill retry 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No CVSS score published by NVD, the CNA, CISA or GitHub so far.
  • No fixed version, patch or mitigation documented.
  • No CISA SSVC assessment.
  • No CWE classification.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-80996 is "net: l2tp: do not propagate multicast notification errors", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.17% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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