VulnerabilityPublished 15 Aug 2026Updated 27 Oct 2026

CVE-2026-72022: Linux kernel · llc: fix SAP refcount leak in llc_ui_autobind()

Affects Linux kernelSource GCVE Database

Not known to be exploited · fixed in 5.15.0-1117.124~20.04.1 : update Linux kernel when convenient.

Data as of 28 Oct 2026, 05:11 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +55

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Patches and advisories

Affected software

Product	Affected	Fixed in
Ubuntu 26.04 LTSlinux`pkg:deb/ubuntu/linux?arch=source&distro=resolute`Other threats	Affected <7.0.0-38.38	Fixed in 7.0.0-38.38
Ubuntu 26.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=resolute`Other threats	Affected <7.0.0-1014.14	Fixed in 7.0.0-1014.14
Ubuntu 26.04 LTSlinux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=resolute`Other threats	Affected <7.0.0-1017.17	Fixed in 7.0.0-1017.17
Ubuntu 26.04 LTSlinux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resolute`Other threats	Affected <7.0.0-1016.16	Fixed in 7.0.0-1016.16
Ubuntu 26.04 LTSlinux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=resolute`Other threats	Affected <7.0.0-1014.14	Fixed in 7.0.0-1014.14
Ubuntu 26.04 LTSlinux-gke`pkg:deb/ubuntu/linux-gke?arch=source&distro=resolute`Other threats	Affected <7.0.0-1008.9	Fixed in 7.0.0-1008.9

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available and has been released in Linux kernel versions 5.15.0-1117.124~20.04.1 and related fixed versions. Users and administrators should update to these fixed kernel versions to resolve the SAP reference count leak. No additional mitigation steps are required beyond applying the official fix.

Description

A reference count leak vulnerability exists in the Linux kernel's llc_ui_autobind() function related to SAP handling. This leak causes SAP entries to remain allocated after socket closure, eventually exhausting dynamic SAP values and causing autobind failures with error -EUSERS. The issue has been fixed in several Linux kernel versions starting with 5.15.0-1117.124~20.04.1 and related releases.

Impact

Repeated use of the vulnerable autobind function can exhaust all dynamic SAP values, preventing new autobind operations and potentially disrupting network communication relying on LLC SAPs. This is a denial-of-service condition affecting the system's ability to allocate SAP resources dynamically. There is no indication of privilege escalation or remote code execution. No known exploits in the wild have been reported.

Summary

The Linux kernel's llc_ui_autobind() function improperly manages reference counts for SAP objects. Specifically, it retains a caller's reference after adding a socket to the SAP hash tables, unlike llc_ui_bind() which correctly drops it. When sockets close, only the socket's reference is released, leaving SAP entries with zero socket count but still present in the SAP list. This leads to resource exhaustion of dynamic SAP values after repeated autobind and close cycles, causing subsequent autobind attempts to fail with -EUSERS. The vulnerability is resolved by dropping the caller's reference after a successful autobind, aligning with the correct ownership model.

GCVE source: db.gcve.eu
OSV ID: UBUNTU-CVE-2026-72022
Osv Schema Version: 1.7.0
Ecosystems: Ubuntu:Pro:14.04:LTS, Ubuntu:Pro:16.04:LTS, Ubuntu:16.04:LTS, Ubuntu:Pro:FIPS-updates:16.04:LTS, Ubuntu:Pro:FIPS:16.04:LTS, Ubuntu:Pro:18.04:LTS, Ubuntu:18.04:LTS, Ubuntu:Pro:FIPS-updates:18.04:LTS, Ubuntu:Pro:FIPS:18.04:LTS, Ubuntu:Pro:20.04:LTS, Ubuntu:20.04:LTS, Ubuntu:Pro:FIPS-updates:20.04:LTS, Ubuntu:Pro:FIPS:20.04:LTS, Ubuntu:22.04:LTS, Ubuntu:Nvidia-BlueField:22.04:LTS, Ubuntu:Pro:Realtime:22.04:LTS, Ubuntu:Pro:FIPS-preview:22.04:LTS, Ubuntu:Pro:FIPS-updates:22.04:LTS, Ubuntu:24.04:LTS, Ubuntu:Nvidia-BlueField:24.04:LTS, Ubuntu:Pro:Realtime:24.04:LTS, Ubuntu:Pro:FIPS-updates:24.04:LTS, Ubuntu:26.04:LTS

References

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