CVE-2026-91947: FreeRDP Server before 3.31.0 Use-After-Free via DRDYNVC
Vulnerability summary
CVE-2026-91947 is a high (CVSS 7.7) vulnerability in freerdp. EPSS estimates a 0.31% chance of exploitation in the next 30 days, higher than 23.7% of scored vulnerabilities. 1 public exploit is recorded.
Public exploit (GitHub, Date unknown)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 1Timeline
- 15-09-2026PublishedVulnerability first disclosed.
- 16-09-2026Last modifiedVulnerability information updated.
Description
FreeRDP server versions before 3.31.0 contain a use-after-free vulnerability in the DRDYNVC parser that dereferences a channel pointer after releasing the synchronization lock. Authenticated clients can race AUDIN channel closure messages against DRDYNVC data parsing to trigger heap-use-after-free when accessing freed channel objects.
CVSS metrics
7 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated7.7HighCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- OSV · DebianEcosystem advisory · calculated7.7HighCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- NVDNIST7.7HighCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.31%
Chance of exploitation in the next 30 days
Percentile
24%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.31% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
1 foundFreerdp
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu3 products
- freerdpAll versions (No fix recorded)
- freerdp2All versions (No fix recorded)
- freerdp3< 3.31.0+dfsg-0ubuntu0.24.04.1 | < 3.31.0+dfsg-0ubuntu0.26.04.1
Debian2 products
- freerdp2All versions (No fix recorded)
- freerdp3All versions (No fix recorded) | < 3.31.0+dfsg-1
Freerdp1 product
- freerdp≥ 2.0.0, < 3.31.0 | < 3.31.0
3 vendors · 6 products
