Is there a patch available for CVE-2026-99173?

Yes, a patch is available for CVE-2026-99173. Update the affected software to the latest version immediately.

Linux CVE-2026-99173

EUVD-2026-111925

2026-10-28 Linux

GHSA-fx9f-7wc6-cjjx

Information Disclosure Linux

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Awaiting Data No severity or threat signals available yet. Label will update when CVSS score is published or threat intelligence arrives.

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AnalysisCVE.org

In the Linux kernel, the following vulnerability has been resolved:

eventfs: Free the eventfs_inode after an rcu grace period too

tracefs_d_revalidate() reads ->is_freed of the eventfs_inode that dentry->d_fsdata points to, and ->d_revalidate() is called in rcu pathwalk mode with nothing but rcu_read_lock() held. The dentry itself stays around for such a walker, but tracefs_d_release() drops its reference to the eventfs_inode when the dentry is killed, and release_ei() then frees it after a grace period of eventfs_srcu. An SRCU grace period doesn't wait for rcu_read_lock() sections, so the walker can read an eventfs_inode that is already gone.

With a pathwalk held up in tracefs_d_revalidate() while the dentry goes away:

BUG: KASAN: slab-use-after-free in tracefs_d_revalidate+0x76/0x90 Read of size 1 at addr ff1100010152d8d0 by task walker/97 Call Trace: <TASK> tracefs_d_revalidate+0x76/0x90 lookup_fast+0x320/0x640 path_lookupat+0x160/0xb00 filename_lookup+0x1f1/0x5b0 vfs_statx+0xd7/0x3b0 vfs_fstatat+0x4d/0x90 __do_sys_newfstatat+0xa0/0x100 do_syscall_64+0x10e/0x5e0 entry_SYSCALL_64_after_hwframe+0x77/0x7f [...] Allocated by task 1: __kmalloc_cache_noprof+0x249/0x560 eventfs_create_dir+0x7a/0x590 event_create_dir+0x2fb/0xcf0 trace_add_event_call+0xbf/0x150 [...] Freed by task 11: kfree+0x1db/0x5b0 srcu_invoke_callbacks+0x3a3/0x620 process_one_work+0x937/0x1810 worker_thread+0x4f1/0xd60

Before commit 8e556432477e ("eventfs: Use SRCU for freeing eventfs_inodes") release_ei() used call_rcu(), which covered the walker, while eventfs_iterate() needs the SRCU grace period. Wait for both and chain call_rcu() from the SRCU callback.

Affected VersionsENISA

Linux patch: 6.18.59

Linux patch: 0

Linux 8e556432477e97ad6179c61b61a32bf5f1af2355 <2cd88c498ecff8e22bf4c397b8eb226db70ac343

Linux patch: 7.3

Linux 6.6.46 <6.7

Linux 6.10.5 <6.11

Linux 8e556432477e97ad6179c61b61a32bf5f1af2355 <4586ef24ce390e8becb9f3e5852d5d3978b01c33

Linux 8e556432477e97ad6179c61b61a32bf5f1af2355 <45fcfd5d9c10e0aa977ed5b9bd445707e01bb107

Linux 2ef3d120d19faba3dec35b10a025b00db0284373

Linux 384f383c5aa7bfd619d9f56a513a36e533428186

Linux patch: 7.2.13

Linux 6.11

Affected Packages

euvd linux fix: 6.7, 6.11

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

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Exploit and PoC references, threat intelligence from 22 sources

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Lifecycle Timeline

Patch available

Oct 28, 2026 - 11:02 EUVD

CVE Published

Oct 28, 2026 - 10:35 cve.org

UNKNOWN (no severity yet)

Threat Intelligence Overview

Data Quality

2 sources

Confidence: Low

EUVD

CVE.org

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity Not scored yet

CISA KEV No

Public POC No

EPSS N/A

Patch available Yes

Active threat No

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

Awaiting Data No severity or threat signals available yet. Label will update when CVSS score is published or threat intelligence arrives.

Attack Technique

Information Disclosure MEDIUM

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.