VulnerabilityPublished 28 Oct 2026

CVE-2026-99181: Linux kernel · autofs: ignore notification errors from a replaced pipe

Source GCVE Database

Authoritative record:CVE-2026-99181

Not known to be exploited · fixed in fb296391f685d82dbb93621a970fb234cea45280 : update Linux kernel when convenient.

Data as of 28 Oct 2026, 13:43 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

Patch: Available – fixed in fb296391f685d82dbb93621a970fb234cea45280, 65676cd4203c0e41a94caf54080a7f0a95434bda, 1a177064f501ed4b67873a43aae5d5bdb18b3704

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Oct 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.

ghsa-q48x-cfgc-jf7c

What to do

Upgrade Linux kernel to fb296391f685d82dbb93621a970fb234cea45280, 65676cd4203c0e41a94caf54080a7f0a95434bda or 1a177064f501ed4b67873a43aae5d5bdb18b3704.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 8d7b48e0bc5fa01a818eac713d4cb0763090cd0e, < fb296391f685d82dbb93621a970fb234cea45280	Fixed in fb296391f685d82dbb93621a970fb234cea45280
LinuxLinux	Affected ≥ 8d7b48e0bc5fa01a818eac713d4cb0763090cd0e, < 65676cd4203c0e41a94caf54080a7f0a95434bda	Fixed in 65676cd4203c0e41a94caf54080a7f0a95434bda
LinuxLinux	Affected ≥ 8d7b48e0bc5fa01a818eac713d4cb0763090cd0e, < 1a177064f501ed4b67873a43aae5d5bdb18b3704	Fixed in 1a177064f501ed4b67873a43aae5d5bdb18b3704
LinuxLinux	Affected =2.6.28	Fixed in–
Red Hatredhat/kernel`pkg:rpm/redhat/kernel`Other threats	Affected =2.6.28	Fixed in–

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

AI-suggested

A fix has been implemented in the Linux kernel to address this issue. Users should apply the updated kernel version containing this patch to prevent denial of service conditions related to autofs daemon restarts. No additional mitigation steps are indicated.

Description

A vulnerability in the Linux kernel autofs subsystem was fixed by changing how notification errors from a replaced pipe are handled. The flaw could cause a denial of service by entering catatonic mode improperly during daemon restarts, disrupting autofs service availability. No memory corruption, privilege escalation, or code execution was observed.

Impact

The vulnerability can cause denial of service of the shared autofs service during daemon restarts by improperly entering catatonic mode and disrupting pipe communication. There is no evidence of memory corruption, information disclosure, privilege escalation, or code execution associated with this flaw.

Summary

The Linux kernel autofs subsystem's autofs_notify_daemon() function improperly handled notification errors from a replaced pipe during daemon restarts. Specifically, if the old pipe's reader closed while a write was blocked, the write returned -EPIPE, causing the system to re-enter catatonic mode incorrectly. This led to closing the replacement pipe and releasing wait queues prematurely, resulting in denial of service of the autofs service. The fix ensures that catatonic mode is only entered if the failing pipe is still the current pipe, making the transition atomic with respect to pipe replacement. The issue was reproduced in a local QEMU guest environment. The impact is limited to denial of service during legitimate daemon restarts with no other security impacts observed.

References

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