How severe is CVE-2026-25959?

CVE-2026-25959 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-25959 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-25959?

CVE-2026-25959 affects Freerdp. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-25959?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-25959 have an EU (EUVD) identifier?

Yes. CVE-2026-25959 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8736.

When was CVE-2026-25959 published?

CVE-2026-25959 was published on 2026-02-25 and last updated on 2026-06-17.

CVE-2026-25959

CVE-2026-25959 is a critical-severity vulnerability in Freerdp with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-416.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 5.5
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-8736
Weakness: CWE-416
Affected product: Freerdp
Published: 2026-02-25
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2026-25959?: 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.
How severe is CVE-2026-25959?: CVE-2026-25959 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-25959 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-25959?: CVE-2026-25959 affects Freerdp. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-25959?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-25959 have an EU (EUVD) identifier?: Yes. CVE-2026-25959 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8736.
When was CVE-2026-25959 published?: CVE-2026-25959 was published on 2026-02-25 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*

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