CVE-2026-25959

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 0.6%, top 56% 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
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: None knownExposed: 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 version 3.23.0, xf_cliprdr_provide_data_ passes freed pDstData to XChangeProperty because the cliprdr channel thread calls xf_cliprdr_server_format_data_response which converts and uses the clipboard data without holding any lock, while the X11 event thread concurrently calls xf_cliprdr_clear_cached_data → HashTable_Clear which frees the same data via xf_cached_data_free, triggering a heap use after free. Version 3.23.0 fixes the issue.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity98% × 45%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
46%
KEV
Not listed

Published

February 25, 2026

Last Modified

June 17, 2026

Advisory Details (9)

Auto-updated Sep 14, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
github Patch Available🟡 PoC Available

Heap-use-after-free in xf_cliprdr_provide_data_ · Advisory · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-78xg-v4p2-4w3c
github_commit

commit d3e8b3b9365b (FreeRDP/FreeRDP)

Fix landed in FreeRDP/FreeRDP commit d3e8b3b9365b — awaiting tagged release

https://github.com/FreeRDP/FreeRDP/commit/d3e8b3b9365be96a4f11dda149d71b3287227d0a
generic

FreeRDP/client/X11/xf_cliprdr.c at 5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L933
generic

FreeRDP/client/X11/xf_cliprdr.c at 5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L2363
generic

FreeRDP/client/X11/xf_cliprdr.c at 5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L2323-L2334
generic

FreeRDP/client/X11/xf_cliprdr.c at 5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L2295
generic

FreeRDP/client/X11/xf_cliprdr.c at 5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L200-L208
generic

FreeRDP/client/X11/xf_cliprdr.c at 5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L1337-L1344
generic

FreeRDP/client/X11/xf_cliprdr.c at 5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L1229-L1243

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 ... 3.23.0+dfsg-1~bpo13+1 (20 versions)3.23.0+dfsg-1—

Weakness Classification(1)

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

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 5× 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. 2026-09-19 21:00 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. 2026-09-01 00:04 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 60 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. 2026-08-15 00:53 UTCVendor advisory
  9. 2026-08-14 21:11 UTCVendor advisory
  10. 2026-08-14 16:22 UTCVendor advisory
  11. 2026-08-14 12:40 UTCVendor advisory
  12. 2026-08-14 08:59 UTCEG score recompute
  13. 2026-08-14 08:59 UTCVendor advisory
  14. 2026-08-13 22:00 UTCEPSS rescore
  15. 2026-08-13 04:40 UTCVendor advisory
  16. 2026-08-13 00:59 UTCEG score recompute
  17. 2026-08-13 00:59 UTCVendor advisory
  18. 2026-08-12 13:50 UTCEPSS rescore
  19. 2026-08-11 23:54 UTCEG score recompute
  20. 2026-08-11 23:54 UTCVendor advisory
  21. 2026-08-11 13:42 UTCEPSS rescore
  22. 2026-08-11 06:19 UTCEG score recompute
  23. 2026-08-11 06:19 UTCVendor advisory
  24. 2026-08-11 00:00 UTCEPSS rescore
  25. 2026-08-10 13:14 UTCVendor advisory
  26. 2026-08-10 08:45 UTCVendor advisory
  27. 2026-08-10 01:15 UTCVendor advisory
  28. 2026-08-09 21:26 UTCVendor advisory
  29. 2026-08-09 17:45 UTCVendor advisory
  30. 2026-08-09 13:49 UTCEG score recompute
  31. 2026-08-09 13:49 UTCVendor advisory
  32. 2026-08-09 13:46 UTCEPSS rescore
  33. 2026-08-09 08:37 UTCEG score recompute
  34. 2026-08-09 08:37 UTCVendor advisory
  35. 2026-08-08 16:37 UTCEPSS rescore
  36. 2026-08-08 11:47 UTCVendor advisory
  37. 2026-08-08 07:44 UTCVendor advisory
  38. 2026-08-08 04:02 UTCVendor advisory
  39. 2026-08-08 00:21 UTCVendor advisory
  40. 2026-08-07 20:40 UTCEG score recompute
  41. 2026-08-07 20:40 UTCVendor advisory
  42. 2026-08-06 13:46 UTCEPSS rescore
  43. 2026-08-06 06:41 UTCVendor advisory
  44. 2026-08-06 02:59 UTCEG score recompute
  45. 2026-08-06 02:59 UTCVendor advisory
  46. 2026-08-05 19:17 UTCEPSS rescore
  47. 2026-08-04 15:10 UTCEPSS rescore
  48. 2026-08-04 05:49 UTCEG score recompute
  49. 2026-08-04 05:49 UTCVendor advisory
  50. 2026-08-03 10:36 UTCEPSS rescore
  51. 2026-08-02 23:13 UTCVendor advisory
  52. 2026-08-02 19:31 UTCEG score recompute
  53. 2026-08-02 19:31 UTCVendor advisory
  54. 2026-08-02 02:26 UTCEPSS rescore
  55. 2026-08-01 04:16 UTCEPSS rescore
  56. 2026-07-30 16:27 UTCEPSS rescore
  57. 2026-07-30 01:30 UTCEPSS rescore
  58. 2026-07-28 15:36 UTCEPSS rescore
  59. 2026-07-27 14:04 UTCEG score recompute
  60. 2026-07-27 13:57 UTCOSV refresh

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-25959?
CVE-2026-25959 is a critical vulnerability published on February 25, 2026. FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, xfcliprdrprovidedata passes freed pDstData to XChangeProperty because the cliprdr channel thread calls xfcliprdrserverformatdataresponse which converts and uses the clipboard data without holding any lock,…
When was CVE-2026-25959 disclosed?
CVE-2026-25959 was first published in the National Vulnerability Database on February 25, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-25959 actively exploited?
CVE-2026-25959 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 54.2% of all scored CVEs.
What is the CVSS score of CVE-2026-25959?
CVE-2026-25959 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-25959?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-25959, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-25959

Explore →

Is Your Infrastructure Affected by CVE-2026-25959?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs