CVE-2026-23534

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 64% 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
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.8Exploit: Elevated riskExposed: 0

A fix is available — apply it.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, a client-side heap buffer overflow occurs in the ClearCodec bands decode path when crafted band coordinates allow writes past the end of the destination surface buffer. A malicious server can trigger a client‑side heap buffer overflow, causing a crash (DoS) and potential heap corruption with code‑execution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
75(Attend)
EG Risk 75/100SSVC: Attend

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
Severity98% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
43%
KEV
Not listed

Published

January 19, 2026

Last Modified

July 15, 2026

Advisory Details (10)

Auto-updated Sep 19, 2026
🔬 Proof of concept available. Patch available. Sources: github, redhat, github_release.
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.6 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:3037
redhat Patch Available

Affected: Red Hat Enterprise Linux 10.0 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:2952
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.4 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:2736
redhat Patch Available

Affected: Red Hat Enterprise Linux 10.

https://access.redhat.com/errata/RHSA-2026:2222
redhat Patch Available

Affected: Red Hat Enterprise Linux 8.

https://access.redhat.com/errata/RHSA-2026:2081
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.

https://access.redhat.com/errata/RHSA-2026:2048
github Patch Available🟡 PoC Available

Heap-buffer-overflow in clear_decompress_bands_data · Advisory · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-3frr-mp8w-4599
github_release Patch Available

3.21.0

Patch available: FreeRDP/FreeRDP 3.21.0

https://github.com/FreeRDP/FreeRDP/releases/tag/3.21.0
generic

FreeRDP/libfreerdp/codec/clear.c at 38514dfa5813aa945a86cfbcec279033f8394468 · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/blob/38514dfa5813aa945a86cfbcec279033f8394468/libfreerdp/codec/clear.c#L883-L884
generic

FreeRDP/libfreerdp/codec/clear.c at 38514dfa5813aa945a86cfbcec279033f8394468 · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/blob/38514dfa5813aa945a86cfbcec279033f8394468/libfreerdp/codec/clear.c#L878-L879

Vendor Advisories for CVE-2026-23534(3)

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

Patch Availability(8)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuwinpr-utils (2.6.1+dfsg1-0ubuntu0.20.04.2+esm1) @ focal2026-05-29ubuntu
ubuntuwinpr3-utils (3.16.0+dfsg-2ubuntu0.3) @ questing2026-05-29ubuntu
redhatfreerdp-2:2.11.7-1.el9_6.12026-02-23redhat
redhatfreerdp-2:3.10.3-3.el10_0.12026-02-18redhat
redhatfreerdp-2:2.11.2-1.el9_4.12026-02-16redhat
redhatfreerdp-2:3.10.3-5.el10_1.12026-02-09redhat
redhatfreerdp-2:2.11.7-1.el9_7.12026-02-05redhat
redhatfreerdp-2:2.11.7-2.el8_102026-02-05redhat

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.

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
freerdp22.10.0+dfsg1-1 ... 2.9.0+dfsg1-1~bpo11+1 (32 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
freerdp22.10.0+dfsg1-1 ... 2.11.7+dfsg1-6~deb12u1 (13 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
freerdp33.15.0+dfsg-2.13.15.0+dfsg-2.1+deb13u1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
freerdp33.15.0+dfsg-2.1 ... 3.20.2+dfsg-1 (14 versions)3.21.0+dfsg-1—

Weakness Classification(1)

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

Additional Vendor Advisories

(5)

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 4× in last 7d / 24× 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.

Showing the most recent 100 of 170 total refreshes for this CVE.

  1. 2026-09-19 17:33 UTCOSV refresh
  2. 2026-09-18 19:27 UTCEPSS rescore
  3. 2026-09-16 14:07 UTCEPSS rescore
  4. 2026-09-16 05:15 UTCEPSS rescore
  5. 2026-09-13 16:47 UTCEPSS rescore
  6. 2026-09-12 15:01 UTCEPSS rescore
  7. 2026-09-11 14:52 UTCEPSS rescore
  8. 2026-09-10 09:34 UTCEPSS rescore
  9. 2026-09-08 22:00 UTCEPSS rescore
  10. 2026-09-07 16:01 UTCEPSS rescore
  11. 2026-09-06 13:47 UTCEPSS rescore
  12. 2026-09-06 13:47 UTCEPSS rescore
  13. 2026-09-04 05:06 UTCEPSS rescore
  14. 2026-09-02 14:11 UTCEPSS rescore
  15. 2026-09-01 13:53 UTCEPSS rescore
  16. 2026-09-01 04:39 UTCEPSS rescore
  17. 2026-08-31 21:04 UTCOSV refresh
  18. 2026-08-30 19:17 UTCEPSS rescore
  19. 2026-08-30 01:22 UTCEPSS rescore
  20. 2026-08-28 21:41 UTCEPSS rescore
  21. 2026-08-27 14:25 UTCEPSS rescore
  22. 2026-08-26 14:46 UTCEPSS rescore
  23. 2026-08-25 13:48 UTCEPSS rescore
  24. 2026-08-23 00:19 UTCEPSS rescore
  25. 2026-08-21 23:49 UTCEPSS rescore
Show 75 more
  1. 2026-08-20 22:55 UTCEPSS rescore
  2. 2026-08-19 17:03 UTCEPSS rescore
  3. 2026-08-18 13:48 UTCEPSS rescore
  4. 2026-08-17 13:47 UTCEPSS rescore
  5. 2026-08-16 14:56 UTCEPSS rescore
  6. 2026-08-16 02:14 UTCEPSS rescore
  7. 2026-08-15 01:30 UTCEPSS rescore
  8. 2026-08-14 23:23 UTCVendor advisory
  9. 2026-08-14 13:44 UTCEG score recompute
  10. 2026-08-14 13:44 UTCVendor advisory
  11. 2026-08-13 22:00 UTCEPSS rescore
  12. 2026-08-12 13:50 UTCEPSS rescore
  13. 2026-08-11 13:42 UTCEPSS rescore
  14. 2026-08-11 00:00 UTCEPSS rescore
  15. 2026-08-09 23:20 UTCVendor advisory
  16. 2026-08-09 19:20 UTCEG score recompute
  17. 2026-08-09 19:20 UTCVendor advisory
  18. 2026-08-09 13:46 UTCEPSS rescore
  19. 2026-08-08 16:37 UTCEPSS rescore
  20. 2026-08-08 08:15 UTCVendor advisory
  21. 2026-08-08 04:16 UTCVendor advisory
  22. 2026-08-08 00:16 UTCEG score recompute
  23. 2026-08-08 00:16 UTCVendor advisory
  24. 2026-08-06 13:46 UTCEPSS rescore
  25. 2026-08-06 09:30 UTCVendor advisory
  26. 2026-08-06 05:30 UTCEG score recompute
  27. 2026-08-06 05:30 UTCVendor advisory
  28. 2026-08-05 19:17 UTCEPSS rescore
  29. 2026-08-04 15:10 UTCEPSS rescore
  30. 2026-08-04 10:38 UTCEPSS rescore
  31. 2026-08-03 10:35 UTCEPSS rescore
  32. 2026-08-02 23:01 UTCEG score recompute
  33. 2026-08-02 23:01 UTCVendor advisory
  34. 2026-08-02 02:26 UTCEPSS rescore
  35. 2026-08-01 04:15 UTCEPSS rescore
  36. 2026-07-30 01:30 UTCEPSS rescore
  37. 2026-07-27 14:13 UTCEPSS rescore
  38. 2026-07-26 14:54 UTCEPSS rescore
  39. 2026-07-26 14:54 UTCEPSS rescore
  40. 2026-07-25 14:17 UTCEPSS rescore
  41. 2026-07-25 14:17 UTCEPSS rescore
  42. 2026-07-24 14:17 UTCEPSS rescore
  43. 2026-07-23 14:18 UTCEPSS rescore
  44. 2026-07-23 14:18 UTCEPSS rescore
  45. 2026-07-23 09:49 UTCOSV refresh
  46. 2026-07-23 03:07 UTCEG score recompute
  47. 2026-07-22 14:08 UTCEPSS rescore
  48. 2026-07-21 15:24 UTCEPSS rescore
  49. 2026-07-21 15:24 UTCEPSS rescore
  50. 2026-07-20 17:08 UTCEPSS rescore
  51. 2026-07-19 02:29 UTCEPSS rescore
  52. 2026-07-19 02:28 UTCEPSS rescore
  53. 2026-07-18 10:04 UTCEPSS rescore
  54. 2026-07-18 10:04 UTCEPSS rescore
  55. 2026-07-16 17:03 UTCEPSS rescore
  56. 2026-07-16 17:03 UTCEPSS rescore
  57. 2026-07-15 16:57 UTCEPSS rescore
  58. 2026-07-15 16:57 UTCEPSS rescore
  59. 2026-07-15 02:21 UTCNVD updateCVSS v3 → 9.8 · severity → CRITICAL
  60. 2026-07-15 02:00 UTCEPSS rescore
  61. 2026-07-15 02:00 UTCEPSS rescore
  62. 2026-07-15 01:21 UTCMITRE cvelistV5CVSS v3 → 7.6 · severity → HIGH
  63. 2026-07-13 22:30 UTCEPSS rescore
  64. 2026-07-13 06:13 UTCEPSS rescore
  65. 2026-07-13 06:13 UTCEPSS rescore
  66. 2026-07-12 05:46 UTCEPSS rescore
  67. 2026-07-12 05:46 UTCEPSS rescore
  68. 2026-07-11 08:27 UTCEPSS rescore
  69. 2026-07-09 19:10 UTCEPSS rescore
  70. 2026-07-08 15:15 UTCEPSS rescore
  71. 2026-07-08 15:15 UTCEPSS rescore
  72. 2026-07-07 13:46 UTCEPSS rescore
  73. 2026-07-06 16:27 UTCEPSS rescore
  74. 2026-07-06 16:27 UTCEPSS rescore
  75. 2026-07-06 05:02 UTCOSV refresh

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-23534?
CVE-2026-23534 is a critical vulnerability published on January 19, 2026. FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, a client-side heap buffer overflow occurs in the ClearCodec bands decode path when crafted band coordinates allow writes past the end of the destination surface buffer. A malicious server can trigger a…
When was CVE-2026-23534 disclosed?
CVE-2026-23534 was first published in the National Vulnerability Database on January 19, 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-2026-23534 actively exploited?
CVE-2026-23534 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 56.8% of all scored CVEs.
What is the CVSS score of CVE-2026-23534?
CVE-2026-23534 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-23534?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-23534, 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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