CVE-2026-55827

HIGHNVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.8 under NVD CVSS v3. EPSS exploit probability: 0.5%, top 59% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Elevated
8.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 8.8Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.1, FreeRDP clients launched with the non-default /cache:codec:rfx option pass desktop stride and height to RemoteFX decoding for Cache Bitmap V3 data while allocating bitmap->data only for the smaller DstWidth and DstHeight in gdi_Bitmap_Decompress, allowing a malicious RDP server to trigger a heap out-of-bounds write with attacker-controlled offset and content. This issue is fixed in version 3.27.1.

CVSS v3
8.8
EG Score
8.8(medium)
EG Risk
56(Track*)
EG Risk 56/100SSVC: Track*

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity88% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS
41.3%
KEV
Not listed

Published

July 10, 2026

Last Modified

July 15, 2026

Advisory Details (4)

Auto-updated Jul 10, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_pr, github_release.
github Patch Available🟡 PoC Available

Heap out-of-bounds write in FreeRDP RemoteFX (RFX) Cache Bitmap V3 decode - malicious RDP server achieves controlled `$pc` in a connecting client · Advisory · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-c495-h83v-3prp
github_release Patch Available

3.27.1

Patch available: FreeRDP/FreeRDP 3.27.1

https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.1
github_pr

Bitmap decode

Fix merged in FreeRDP/FreeRDP PR #12899 on 2026-06-16 — awaiting tagged release

https://github.com/FreeRDP/FreeRDP/pull/12899
github_commit

commit e58adf922ea4 (FreeRDP/FreeRDP)

Fix landed in FreeRDP/FreeRDP commit e58adf922ea4 — awaiting tagged release

https://github.com/FreeRDP/FreeRDP/commit/e58adf922ea4c0d5495e59a1fe488d70092e0e3e

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 9× in last 7d / 25× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-23 03:20 UTCEG score recompute
  2. 2026-07-22 14:08 UTCEPSS rescore
  3. 2026-07-21 15:25 UTCEPSS rescore
  4. 2026-07-20 17:08 UTCEPSS rescore
  5. 2026-07-19 14:31 UTCEPSS rescore
  6. 2026-07-19 14:31 UTCEPSS rescore
  7. 2026-07-19 02:29 UTCEPSS rescore
  8. 2026-07-18 10:04 UTCEPSS rescore
  9. 2026-07-16 17:03 UTCEPSS rescore
  10. 2026-07-15 17:49 UTCEG score recompute▲ 1.30
  11. 2026-07-15 16:57 UTCEPSS rescore
  12. 2026-07-15 16:57 UTCEPSS rescore
  13. 2026-07-15 06:20 UTCNVD updateCVSS v3 → 8.8
  14. 2026-07-15 04:44 UTCEG score recompute▼ 1.30
  15. 2026-07-15 04:19 UTCMITRE cvelistV5CVSS v3 → 7.5
  16. 2026-07-15 02:00 UTCEPSS rescore
  17. 2026-07-15 02:00 UTCEPSS rescore
  18. 2026-07-14 02:23 UTCEG score recompute▲ 1.30
  19. 2026-07-14 00:27 UTCNVD updateCVSS v3 → 8.8
  20. 2026-07-13 22:31 UTCEPSS rescore
  21. 2026-07-13 06:13 UTCEPSS rescore
  22. 2026-07-13 06:13 UTCEPSS rescore
  23. 2026-07-12 05:46 UTCEPSS rescore
  24. 2026-07-10 20:04 UTCEG score recompute
  25. 2026-07-10 20:02 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-55827?
CVE-2026-55827 is a high vulnerability published on July 10, 2026. FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.1, FreeRDP clients launched with the non-default /cache:codec:rfx option pass desktop stride and height to RemoteFX decoding for Cache Bitmap V3 data while allocating bitmap->data only for the smaller DstWidth and…
When was CVE-2026-55827 disclosed?
CVE-2026-55827 was first published in the National Vulnerability Database on July 10, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55827 actively exploited?
CVE-2026-55827 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 41.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-55827?
CVE-2026-55827 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2026-55827?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55827, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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