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CVE-2026-33983

FreeRDP: Progressive Codec Quant BYTE Underflow - UB + CPU DoS

Published: Mar 30, 2026Updated: Apr 1, 2026 Sources: CVE List NVD BDUCWE-190
NVD MITRE
6.5CVSSMEDIUM
EPSS Score
0.3%
Top 83.8%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, progressive_decompress_tile_upgrade() detects a mismatch via progressive_rfx_quant_cmp_equal() but only emits WLog_WARN, execution continues. The wrapped value (247) is used as a shift exponent, causing undefined behavior and an approximately 80 billion iteration loop (CPU DoS). This issue has been patched in version 3.24.2.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:RS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:RUser Interaction
Required
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-190CWE-252

Affected Products

freerdpfreerdpOSS Libraries
FreeRDPFreeRDPOSS Libraries
АЛЬТ СП 10АО «ИВК»
On-premOS
Operating Systems / linux-distro
FreeRDPFree Software Foundation, Inc.OSS Libraries
freerdposs-projectUSOSS Libraries
ао «ивк»commercialRUOperating Systemsaka ivk
free software foundation, inc.oss-projectUSOSS Librariesaka fsf, free software foundation

Attack Graph

Products CVE Techniques Tactics

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Exploitability

Official Patch Available

MITRE ATT&CK

1 technique
Initial Access
View detailed technique mapping

References

https://github.com/FreeRDP/FreeRDP/commit/78188ab479c8e6eb9ba2475b3732c76b4bbe5425
github.com
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-4gfm-4p52-h478
github.com
https://altsp.su/obnovleniya-bezopasnosti/
altsp.su

Timeline

Published
Mar 30, 2026
Last Updated
Apr 1, 2026

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