CVE-2026-91963 (CVSS 6.5)

Description

FreeRDP versions before 3.31.0 contain an uninitialized heap memory disclosure vulnerability in the urbdrc USB redirection channel. A malicious RDP server can induce failing USB transfers to read uninitialized heap memory from the client, defeating ASLR and enabling remote code execution when chained with memory corruption vulnerabilities.

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CVSS v3.1 Score

6.5

MEDIUM

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

EPSS — Exploit Prediction

0.0067

Probability of exploitation

0.51%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-457 CWE-457

References

Other References

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-hw7p-5h2r-83gq https://www.vulncheck.com/advisories/freerdp-2.0.0-through-3.30.0-uninitialized-heap-memory-disclosure-via-urbdrc https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-hw7p-5h2r-83gq

Frequently Asked Questions

What is CVE-2026-91963? +

FreeRDP versions before 3.31.0 contain an uninitialized heap memory disclosure vulnerability in the urbdrc USB redirection channel. A malicious RDP server can induce failing USB transfers to read uninitialized heap memory from the client, defeating ASLR and enabling remote code execution when chained with memory corruption vulnerabilities. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-91963? +

CVE-2026-91963 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0067, placing it in the 1th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-91963? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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