0.0
NA
CVE-2026-99181
autofs: ignore notification errors from a replaced pipe
Description

In the Linux kernel, the following vulnerability has been resolved: autofs: ignore notification errors from a replaced pipe autofs_notify_daemon() takes a reference to the current notification pipe under wq_mutex, then drops the mutex before writing the request. The write can block while the daemon enters catatonic mode and installs a replacement pipe. If the old pipe's reader is then closed, the delayed write returns -EPIPE and the generic error path enters catatonic mode again. That transition acts on the current superblock state, closes the replacement pipe, and releases the new daemon generation's wait queues. Only enter catatonic mode when the pipe which failed is still the current pipe. Factor the already-locked transition so the identity check and state change are atomic with respect to another replacement. This was reproduced on v7.3-rc5-337-gff47652a4b66c in a local QEMU guest. An unprivileged UID 65534 lookup filled the old packet pipe before a normal CATATONIC/SETPIPEFD restart. On the unmodified kernel, the new pipe received HUP and both a pending victim lookup and a later lookup failed with ENOENT in two out of two fresh-mount runs. With this change, the new pipe remained active, received an intact 304-byte request, and both victim lookups completed in two out of two runs. Normal lookup and restart-without-a-blocked-writer controls passed. No KASAN, oops, refcount, or lock diagnostic was observed. A source reproducer and complete local logs are available privately on request. The demonstrated impact is limited to denial of a shared autofs service during a legitimate daemon restart. No memory corruption, information leak, privilege escalation, or code execution primitive was observed.

INFO

Published Date :

Oct. 28, 2026, 11:17 a.m.

Last Modified :

Oct. 28, 2026, 11:17 a.m.

Remotely Exploit :

No

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products

The following products are affected by CVE-2026-99181 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
Solution
Fix autofs to avoid entering catatonic mode on pipe errors.
  • Apply the provided kernel patch.
  • Ensure pipe identity checks are atomic.
  • Test the updated autofs service functionality.
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-2026-99181.

URL Resource
https://git.kernel.org/stable/c/1a177064f501ed4b67873a43aae5d5bdb18b3704
https://git.kernel.org/stable/c/65676cd4203c0e41a94caf54080a7f0a95434bda
https://git.kernel.org/stable/c/fb296391f685d82dbb93621a970fb234cea45280
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-99181 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-2026-99181 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).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-99181 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-99181 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.

  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Oct. 28, 2026

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: autofs: ignore notification errors from a replaced pipe autofs_notify_daemon() takes a reference to the current notification pipe under wq_mutex, then drops the mutex before writing the request. The write can block while the daemon enters catatonic mode and installs a replacement pipe. If the old pipe's reader is then closed, the delayed write returns -EPIPE and the generic error path enters catatonic mode again. That transition acts on the current superblock state, closes the replacement pipe, and releases the new daemon generation's wait queues. Only enter catatonic mode when the pipe which failed is still the current pipe. Factor the already-locked transition so the identity check and state change are atomic with respect to another replacement. This was reproduced on v7.3-rc5-337-gff47652a4b66c in a local QEMU guest. An unprivileged UID 65534 lookup filled the old packet pipe before a normal CATATONIC/SETPIPEFD restart. On the unmodified kernel, the new pipe received HUP and both a pending victim lookup and a later lookup failed with ENOENT in two out of two fresh-mount runs. With this change, the new pipe remained active, received an intact 304-byte request, and both victim lookups completed in two out of two runs. Normal lookup and restart-without-a-blocked-writer controls passed. No KASAN, oops, refcount, or lock diagnostic was observed. A source reproducer and complete local logs are available privately on request. The demonstrated impact is limited to denial of a shared autofs service during a legitimate daemon restart. No memory corruption, information leak, privilege escalation, or code execution primitive was observed.
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/99xxx/CVE-2026-99181.json">CVE-2026-99181</a>
    Added Reference https://git.kernel.org/stable/c/1a177064f501ed4b67873a43aae5d5bdb18b3704
    Added Reference https://git.kernel.org/stable/c/65676cd4203c0e41a94caf54080a7f0a95434bda
    Added Reference https://git.kernel.org/stable/c/fb296391f685d82dbb93621a970fb234cea45280
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.