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.NET
.NET NuGet
Not in CISA KEV
HIGH severity

CVE-2026-39959 — Tmds.DBus

HIGH

CVE-2026-39959 is a high-severity (CVSS 7.1) CWE-290 vulnerability in Tmds.DBus. A fix is available for Tmds.DBus — see the affected versions and patch details below.

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

Also known asGHSA-xrw6-gwf8-vvr9
Published
Updated
Affected
3 pkgs
Patched
3 / 3
Exploits
None indexed
Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-39959.

EPSS Exploitation Probability

via FIRST.org ↗
0.1%probability of exploitation in next 30 days
Lower Risk+0.00%
Lower risk than most CVEs2th percentile — riskier than 2% of all scored CVEsHighest risk
0.00%0.21%0.42%0.63%0.0%0.1%May 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

3 pkgs affected
.NETTmds.DBus.NETTmds.DBus.Protocol.NETTmds.DBus.Protocol

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.

Description

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.

Affected Packages

3 total 3 fixed
EcosystemPackageVulnerable rangeFix
.NETNuGetTmds.DBusall versions0.92.0dotnet add package Tmds.DBus --version 0.92.0
.NETNuGetTmds.DBus.Protocolall versions0.21.3dotnet add package Tmds.DBus.Protocol --version 0.21.3
.NETNuGetTmds.DBus.Protocol≥ 0.22.0&&< 0.92.00.92.0dotnet add package Tmds.DBus.Protocol --version 0.92.0

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Tmds.DBus, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update Tmds.DBus to 0.92.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-39959 is resolved across your whole dependency graph.

  3. Workarounds

    Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

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. Us
O3 Security · Impact-Aware SCA

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CVE-2026-39959: Tmds.DBus — Fixed in 0.92.0