CVE-2026-33987: freerdp Heap-based Buffer Overflow

Vulnerability summary

CVE-2026-33987 is a high (CVSS 7.1) Heap-based Buffer Overflow vulnerability in freerdp. EPSS estimates a 0.15% chance of exploitation in the next 30 days, higher than 3.5% of scored vulnerabilities.

Timeline

1. 30-03-2026
   PublishedVulnerability first disclosed.
2. 31-03-2026
   Last modifiedVulnerability information updated.

Description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, in persistent_cache_read_entry_v3() in libfreerdp/cache/persistent.c, persistent->bmpSize is updated before winpr_aligned_recalloc(). If realloc fails, bmpSize is inflated while bmpData points to the old buffer. This issue has been patched in version 3.24.2.

• CWE-122Heap-based Buffer OverflowA heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
• CWE-131Incorrect Calculation of Buffer SizeThe product does not correctly calculate the size to be used when allocating a buffer, which could lead to a buffer overflow.