Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2026-58093— Kernel use-after-free via tty ioctls

Quick assessment

Affected
FreeBSD FreeBSD
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

TIOCSCTTY 的 ioctl 处理程序在获取进程树锁之前释放了 tty 锁。在重新获取 tty 锁后，处理程序未重新验证终端的状态，可能会将正在被并发销毁的终端链接到调用进程所在的会话中。 非特权本地用户可利用此竞态条件提升权限。

AI Predicted 7.8 Difficulty: Hard EPSS 0.13% · P3

Possible ATT&CK Techniques 1 AI

T1068 · Exploitation for Privilege Escalation

Affected Version Matrix 3

VendorProduct Version RangeStatus
FreeBSD FreeBSD 15.1-RELEASE< p3 affected
15.0-RELEASE< p13 affected
14.4-RELEASE< p9 affected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-58093

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Kernel use-after-free via tty ioctls
Source: CVE Program / CVE List V5
Vulnerability Description
The TIOCSCTTY ioctl handler drops the tty lock in order to acquire the process tree lock. After reacquiring the tty lock, the handler did not revalidate the state of the terminal, and could proceed to link a terminal that was concurrently being destroyed to the calling process' session. An unprivileged local user can exploit this race condition to escalate privileges.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
使用共享资源的并发执行不恰当同步问题(竞争条件)
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
FreeBSD FreeBSD 15.1-RELEASE ~ p3 -

II. Public POCs for CVE-2026-58093

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-58093

请登录查看更多情报信息。

Vendor Advisories for CVE-2026-58093 (2)

Same Patch Batch · FreeBSD · 2026-08-26 · 9 CVEs total

CVE-2026-58090 Use-after-free in unix SOCK_STREAM message handling
CVE-2026-58091 Kernel use-after-free via the SNDCTL_DSP_SYNCSTART ioctl
CVE-2026-58092 Unauthorized credential switching
CVE-2026-58089 hwpmc fails to detach PMCs during exec credential transitions
CVE-2026-58097 ppp(8): missing length validation in mp_SetEnddisc()
CVE-2026-58095 ppp(8): incorrect length calculation in mp_Enddisc()
CVE-2026-58096 ppp(8): missing length validation in LcpDecodeConfig()
CVE-2026-58094 TOCTOU race in POSIX shared memory large page configuration

IV. Related Vulnerabilities

Same product: FreeBSD
Same vendor: FreeBSD
Same weakness: CWE-362

V. Comments for CVE-2026-58093

No comments yet

Leave a comment