Vulnerability Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a size_t underflow in the IMA-ADPCM and MS-ADPCM audio decoders leads to heap-buffer-overflow write via the RDPSND audio channel. In libfreerdp/codec/dsp.c, the IMA-ADPCM and MS-ADPCM decoders subtract block header sizes from a size_t variable without checking for underflow. When nBlockAlign (received from the server) is set such that size % block_size == 0 triggers the header parsing at a point where size is smaller than the header (4 or 8 bytes), the subtraction wraps size to ~SIZE_MAX. The while (size > 0) loop then continues for an astronomical number of iterations. This vulnerability is fixed in 3.24.0.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Freerdp | Freerdp | < 3.24.0 |
Related Weaknesses (CWE)
References
- https://github.com/FreeRDP/FreeRDP/commit/16df2300e1e3f5a51f68fb1626429e58b531b7Patch
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-85x9-4xxp-xhm5ExploitPatchVendor Advisory
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-85x9-4xxp-xhm5ExploitPatchVendor Advisory
FAQ
What is CVE-2026-31883?
CVE-2026-31883 is a vulnerability with a CVSS score of 6.5 (MEDIUM). FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a size_t underflow in the IMA-ADPCM and MS-ADPCM audio decoders leads to heap-buffer-overflow write via the RDPSND aud...
How severe is CVE-2026-31883?
CVE-2026-31883 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-31883?
Check the references section above for vendor advisories and patch information. Affected products include: Freerdp Freerdp.