Quick answers
- Is CVE-2026-121387 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-121387 being exploited in the wild.
- How severe is CVE-2026-121387?
- Medium severity, with a CVSS score of 4.3, published 3 November 2026.
- Which products and versions are affected?
- FreeRDP 2.0.0 through 3.32.1.
- Is there a fix for CVE-2026-121387?
- Yes: fixed in 3.32.2. Until then: Disable audio playback, or build FreeRDP with FFmpeg DSP backend (WITH_DSP_FFMPEG=ON) instead of the built-in GSM decoder, or avoid connecting to untrusted RDP servers. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-121387 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-121387?
- Check whether you run FreeRDP at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: 3.32.2
Disable audio playback, or build FreeRDP with FFmpeg DSP backend (WITH_DSP_FFMPEG=ON) instead of the built-in GSM decoder, or avoid connecting to untrusted RDP servers.
Technical details
An out-of-bounds read vulnerability exists in the freerdp_dsp_decode_gsm610 function when decoding GSM610 WAV49 audio frames. The decoder calls the lengthless gsm_decode API before validating that a complete 32- or 33-byte frame is available, allowing a malicious server to supply truncated audio data that causes libgsm to read past the buffer boundary. The vulnerability requires the victim to connect to a malicious RDP server with audio enabled, specific build configuration (WITH_GSM=ON and WITH_DSP_FFMPEG=OFF), and GSM610 codec negotiation.
Affected products
- FreeRDP 2.0.0 through 3.32.1
Timeline
- 2026-10-19: disclosed: GitHub Security Advisory published
- 2026-11-03: patched: Fixed in version 3.32.2