Medium

Unauthorized process termination in policycoreutils seunshare killall()

IdentifiersCVE-2026-59677CWE-862· Missing Authorization

CVE-2026-59677 is a local missing-authorization vulnerability in the SELinux userspace utility seunshare, affecting policycoreutils through version 3.10. The flaw is in the killall() functionality exposed through the --kill and -Z options. When these options are combined, seunshare kills processes matching a user-supplied SELinux context without adequately restricting whether the caller is authorized to terminate those processes. On systems where seunshare is installed setuid-root and executes from an unconfined SELinux domain, an unconfined local user can cause termination of processes, including root-owned processes, that are also running in an unconfined context. The issue is primarily a local denial-of-service condition caused by improper authorization checks around privileged process signaling behavior.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows an unprivileged local user running in an unconfined SELinux context to terminate processes they should not be permitted to kill, including root-owned processes in the same unconfined context. This can disrupt services, terminate administrative or security-relevant workloads, and cause local denial of service. In environments using the default targeted SELinux policy, where seunshare may execute without a domain transition out of the unconfined domain, the practical impact can extend to root-like interference with system operation despite SELinux enforcement.

Mitigation

If you can’t patch tonight, do this now.

If an updated package is not immediately available, disable access to the vulnerable functionality by removing setuid-root from seunshare or restricting execution of seunshare to trusted administrators only. Prevent use of the --kill capability where possible, and avoid exposing seunshare to untrusted local users on systems where it runs in an unconfined SELinux context. Additional hardening can include ensuring the utility does not execute with privileges or SELinux domain behavior that permits unauthorized signaling of other users' or root-owned processes.

Remediation

Patch, then assume compromise.

Upgrade to SELinux userspace utilities version 3.11 or a downstream backport that includes the upstream fix for CVE-2026-59677. The upstream remediation removed the --kill switch and the associated killall() functionality, eliminating the vulnerable behavior. Where vendor packages provide a patched policycoreutils build, deploy that update instead of retaining version 3.10 behavior.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

SelinuxPolicycoreutilsapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

2 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

2 SOURCESView more in app

security opensuseNews

Jul 15, 2026

SELinux Userspace Utilities: Local Denial-of-Service Attack Vectors in seunshare in release 3.10 | SUSE Security Team Blog

A local process-killing vulnerability in seunshare’s killall() logic where combining --kill and -Z allows an unconfined user to terminate processes, including root-owned unconfined processes, based on a supplied SELinux context.

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Exposure mapping

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Threat actor evidence

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Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

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Vendor-by-vendor mapping

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Social activity1