CVE-2026-26955

HIGHPre-NVD 8.88.8
EchelonGraph scoreLOW confidence

This high-severity CVE scores 8.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). 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: secondary
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

A fix is available — apply it.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, a malicious RDP server can trigger a heap buffer overflow in FreeRDP clients using the GDI surface pipeline (e.g., xfreerdp) by sending an RDPGFX ClearCodec surface command with an out-of-bounds destination rectangle. The gdi_SurfaceCommand_ClearCodec() handler does not call is_within_surface() to validate the command rectangle against the destination surface dimensions, allowing attacker-controlled cmd->left/cmd->top (and subcodec rectangle offsets) to reach image copy routines that write into surface->data without bounds enforcement. The OOB write corrupts an adjacent gdiGfxSurface struct's codecs* pointer with attacker-controlled pixel data, and corruption of codecs* is sufficient to reach an indirect function pointer call (NSC_CONTEXT.decode at nsc.c:500) on a subsequent codec command — full instruction pointer (RIP) control demonstrated in exploitability harness. Users should upgrade to version 3.23.0 to receive a patch.

CVSS v3
8.8
EG Score
8.8(low)
EPSS
41.4%
KEV
Not listed

Published

February 25, 2026

Last Modified

June 30, 2026

Advisory Details (10)

Auto-updated Jun 30, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github, redhat.
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions.

https://access.redhat.com/errata/RHSA-2026:6395
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.6 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:6385
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.4 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:6384
redhat Patch Available

Affected: Red Hat Enterprise Linux 8.

https://access.redhat.com/errata/RHSA-2026:6005
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.

https://access.redhat.com/errata/RHSA-2026:6004
redhat Patch Available

Affected: Red Hat Enterprise Linux 10.

https://access.redhat.com/errata/RHSA-2026:5939
redhat Patch Available

Affected: Red Hat Enterprise Linux 10.0 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:5936
redhat Patch Available

Affected: Red Hat Enterprise Linux 10.

https://access.redhat.com/errata/RHSA-2026:19033
github Patch Available🟡 PoC Available

Out-of-bounds Write in freerdp · Advisory · FreeRDP/FreeRDP · GitHub

Affected: 3.21.0. Those fixes hardened the

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-mr6w-ch7c-mqqj
github_commit

commit 7d8fdce2d0ef (FreeRDP/FreeRDP)

Fix landed in FreeRDP/FreeRDP commit 7d8fdce2d0ef — awaiting tagged release

https://github.com/FreeRDP/FreeRDP/commit/7d8fdce2d0ef337cb86cb37fc0c436c905e04d77

Vendor Advisories for CVE-2026-26955(8)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(15)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuwinpr3-utils (3.16.0+dfsg-2ubuntu0.3) @ questing2026-06-30ubuntu
redhatfreerdp-2:3.10.3-12.el10_2.22026-05-19redhat
redhatfreerdp-0:2.1.1-5.el7_9.52026-04-09redhat
redhatfreerdp-2:2.2.0-12.el8_8.32026-04-07redhat
redhatfreerdp-2:2.2.0-10.el8_42026-04-06redhat
redhatfreerdp-2:2.2.0-7.el8_6.32026-04-06redhat
redhatfreerdp-2:2.0.0-46.rc4.el8_2.82026-04-06redhat
redhatfreerdp-2:2.11.2-1.el9_4.32026-04-01redhat
redhatfreerdp-2:2.4.1-3.el9_0.22026-04-01redhat
redhatfreerdp-2:2.4.1-6.el9_2.42026-04-01redhat
redhatfreerdp-2:2.11.7-1.el9_6.52026-04-01redhat
redhatfreerdp-2:2.11.7-4.el8_102026-03-30redhat
redhatfreerdp-2:2.11.7-1.el9_7.32026-03-30redhat
redhatfreerdp-2:3.10.3-3.el10_0.32026-03-26redhat
redhatfreerdp-2:3.10.3-5.el10_1.32026-03-26redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(2)

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

Additional Vendor Advisories

(7)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 10× in last 7d / 19× 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. 2026-07-11 08:27 UTCEPSS rescore
  2. 2026-07-09 19:10 UTCEPSS rescore
  3. 2026-07-08 15:15 UTCEPSS rescore
  4. 2026-07-08 15:15 UTCEPSS rescore
  5. 2026-07-07 13:46 UTCEPSS rescore
  6. 2026-07-06 16:27 UTCEPSS rescore
  7. 2026-07-06 16:27 UTCEPSS rescore
  8. 2026-07-06 02:23 UTCEPSS rescore
  9. 2026-07-06 02:23 UTCEPSS rescore
  10. 2026-07-05 02:30 UTCEPSS rescore
  11. 2026-07-04 06:31 UTCEPSS rescore
  12. 2026-07-04 06:31 UTCEPSS rescore
  13. 2026-07-01 15:06 UTCEPSS rescore
  14. 2026-07-01 15:06 UTCEPSS rescore
  15. 2026-06-30 23:22 UTCEPSS rescore
  16. 2026-06-30 23:22 UTCEPSS rescore
  17. 2026-06-30 04:41 UTCEG score recompute
  18. 2026-06-30 04:41 UTCVendor advisory
  19. 2026-06-30 04:31 UTCNVD updatefirst tracked

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-26955?
CVE-2026-26955 is a high vulnerability published on February 25, 2026. FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, a malicious RDP server can trigger a heap buffer overflow in FreeRDP clients using the GDI surface pipeline (e.g., xfreerdp) by sending an RDPGFX ClearCodec surface command with an out-of-bounds destination…
When was CVE-2026-26955 disclosed?
CVE-2026-26955 was first published in the National Vulnerability Database on February 25, 2026, with the most recent update on June 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-26955 actively exploited?
CVE-2026-26955 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 41.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-26955?
CVE-2026-26955 has a CVSS v3 base score of 8.8 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-26955?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-26955, 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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