7.1

CVE-2026-55564: freerdp Out-of-bounds Read

CVSS: 7.1v3.1HighAnalyzed
AliasesUBUNTU-CVE-2026-55564DEBIAN-CVE-2026-55564
Published 19-08-2026Last modified 25-08-2026
Open JSON

Vulnerability summary

CVE-2026-55564 is a high (CVSS 7.1) Out-of-bounds Read vulnerability in freerdp. EPSS estimates a 0.44% chance of exploitation in the next 30 days, higher than 36.8% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
38/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.1/10
010
High · v3.1 (NVD)
EPSS score
0.44%
0%100%
Low · +0.11 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github

Advisory lineage

Upstream 0 · Downstream 1 · Related 1
USN-8561-1

Timeline

  1. 19-08-2026
    PublishedVulnerability first disclosed.
  2. 25-08-2026
    Last modifiedVulnerability information updated.

Description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, the glyph_cache_get function in libfreerdp/cache/glyph.c checks whether index is greater than cache->number instead of greater than or equal to it. A malicious RDP server can use GLYPH_FRAGMENT_USE replay in update_process_glyph_fragments to make the default cache receive index 254 when cache->number is 254, reading one pointer beyond the entries array and dereferencing it as a glyph. This can crash the client and may disclose adjacent heap data. This issue is fixed in version 3.27.0.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.44%

Chance of exploitation in the next 30 days

Percentile

37%

Versus all other CVEs

30-day change

+0.11 pp

From 0.33% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.44%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • githubUnverified

    Freerdp

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Ubuntu3 products
  • freerdpAll versions (No fix recorded)
  • freerdp2All versions (No fix recorded)
  • freerdp3< 3.30.0+dfsg-0ubuntu0.24.04.1 | All versions (No fix recorded) | < 3.30.0+dfsg-0ubuntu0.26.04.1
Debian2 products
  • freerdp2All versions (No fix recorded)
  • freerdp3All versions (No fix recorded) | < 3.27.0+dfsg-1
Freerdp1 product

3 vendors · 6 products

References

8 links