How severe is CVE-2026-44421?

CVE-2026-44421 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-44421 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-44421?

CVE-2026-44421 affects Freerdp. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-44421?

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

Does CVE-2026-44421 have an EU (EUVD) identifier?

Yes. CVE-2026-44421 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-33433.

When was CVE-2026-44421 published?

CVE-2026-44421 was published on 2026-05-29 and last updated on 2026-07-08.

CVE-2026-44421

CVE-2026-44421 is a high-severity vulnerability in Freerdp with a CVSS 3.x base score of 8.8. 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-122.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 0% (34th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-33433
Weakness: CWE-122
Affected product: Freerdp
Published: 2026-05-29
Last modified: 2026-07-08

Description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, a malicious RDP server can trigger a heap-buffer-overflow write in the FreeRDP client by sending crafted RDPGFX PDUs. The bug is in gdi_CacheToSurface: it validates a destination rectangle that is clamped to UINT16_MAX, but then performs the copy using the original cacheEntry->width/height. This can cause a large out-of-bounds heap write and may lead to client crashes or code execution. This bug is reachable from a malicious RDP server, but only when the client has RDPGFX enabled. This vulnerability is fixed in 3.26.0.

Frequently asked questions

What is CVE-2026-44421?: FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, a malicious RDP server can trigger a heap-buffer-overflow write in the FreeRDP client by sending crafted RDPGFX PDUs. The bug is in gdi_CacheToSurface: it validates a destination rectangle that is clamped to UINT16_MAX, but then performs the copy using the original cacheEntry->width/height. This can cause a large out-of-bounds heap write and may lead to client crashes or code execution. This bug is reachable from a malicious RDP server, but only when the client has RDPGFX enabled. This vulnerability is fixed in 3.26.0.
How severe is CVE-2026-44421?: CVE-2026-44421 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-44421 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-44421?: CVE-2026-44421 affects Freerdp. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-44421?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-44421 have an EU (EUVD) identifier?: Yes. CVE-2026-44421 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-33433.
When was CVE-2026-44421 published?: CVE-2026-44421 was published on 2026-05-29 and last updated on 2026-07-08.

References

Affected products (1)

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

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