Tmds.DBus: malicious D-Bus peers can spoof signals, exhaust file descriptor resources, and cause denial of service

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.1 · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

EPSS

• CVE-2026-39959: 0.12% estimated exploitation activity in the next 30 days; percentile 2.15 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Tmds.DBus and Tmds.DBus.Protocol are vulnerable to malicious D-Bus peers. A peer on the same bus can spoof signals by impersonating the owner of a well-known name, exhaust system resources or cause file descriptor spillover by sending messages with an excessive number of Unix file descriptors, and crash the application by sending malformed message bodies that cause unhandled exceptions on the SynchronizationContext. Patches The vulnerabilities are fixed in version 0.92.0. For Tmds.DBus.Protocol, the fixes are also backported to 0.21.3. Workarounds There are no known workarounds. Users should upgrade to a patched version.

Published by the source

8 Apr 2026, 19:52 UTC

Last modified by the source

9 Apr 2026, 19:05 UTC

Source last checked

26 Oct 2026, 17:04 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-xrw6-gwf8-vvr9

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# Patch Next advisory brief: CVE-2026-39959

Advisory: Tmds.DBus: malicious D-Bus peers can spoof signals, exhaust file descriptor resources, and cause denial of service
IDs: CVE-2026-39959, GHSA-xrw6-gwf8-vvr9
Record: https://patchnext.com/advisories/cve-2026-39959 (revision 1, source checked 26 Oct 2026, 17:04 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: tmds.dbus.protocol 0.92.0, 0.21.3; tmds.dbus 0.92.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet tmds.dbus.protocol: affected < 0.21.3; >= 0.22.0, < 0.92.0; fixed in 0.92.0, 0.21.3
- NuGet tmds.dbus: affected < 0.92.0; fixed in 0.92.0

## Suggested inspection (read-only)
- NuGet tmds.dbus.protocol: check the installed version with your package manager.
- NuGet tmds.dbus: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on tmds.dbus.protocol, tmds.dbus.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-xrw6-gwf8-vvr9 (GitHub-reviewed advisory GHSA-xrw6-gwf8-vvr9 lists affected ranges: NuGet tmds.dbus >=0 =0 =0.22.0 <0.92.0)

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