CVE-2026-33983: freerdp Integer Overflow or Wraparound

Vulnerability summary

CVE-2026-33983 is a medium (CVSS 6.5) Integer Overflow or Wraparound vulnerability in freerdp. EPSS estimates a 0.80% chance of exploitation in the next 30 days, higher than 55.7% of scored vulnerabilities.

Timeline

1. 30-03-2026
   PublishedVulnerability first disclosed.
2. 15-07-2026
   Last modifiedVulnerability information updated.

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.

• CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
• CWE-252Unchecked Return ValueThe product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions.