How severe is CVE-2026-33977?

CVE-2026-33977 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-33977 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33977?

CVE-2026-33977 affects Freerdp. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-33977?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-33977 have an EU (EUVD) identifier?

Yes. CVE-2026-33977 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17223.

When was CVE-2026-33977 published?

CVE-2026-33977 was published on 2026-03-30 and last updated on 2026-06-17.

CVE-2026-33977

CVE-2026-33977 is a medium-severity vulnerability in Freerdp with a CVSS 3.x base score of 6.5. 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-617.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v4: 6.9
EPSS exploit prediction: 0% (17th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-17223
Weakness: CWE-617
Affected product: Freerdp
Published: 2026-03-30
Last modified: 2026-06-17

Description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, a malicious RDP server can crash the FreeRDP client by sending audio data in IMA ADPCM format with an invalid initial step index value (>= 89). The unvalidated step index is read directly from the network and used to index into a 89-entry lookup table, triggering a WINPR_ASSERT() failure and process abort via SIGABRT. This affects any FreeRDP client that has audio redirection (RDPSND) enabled, which is the default configuration. This issue has been patched in version 3.24.2.

Frequently asked questions

What is CVE-2026-33977?: FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, a malicious RDP server can crash the FreeRDP client by sending audio data in IMA ADPCM format with an invalid initial step index value (>= 89). The unvalidated step index is read directly from the network and used to index into a 89-entry lookup table, triggering a WINPR_ASSERT() failure and process abort via SIGABRT. This affects any FreeRDP client that has audio redirection (RDPSND) enabled, which is the default configuration. This issue has been patched in version 3.24.2.
How severe is CVE-2026-33977?: CVE-2026-33977 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-33977 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33977?: CVE-2026-33977 affects Freerdp. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-33977?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-33977 have an EU (EUVD) identifier?: Yes. CVE-2026-33977 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17223.
When was CVE-2026-33977 published?: CVE-2026-33977 was published on 2026-03-30 and last updated on 2026-06-17.

References

Affected products (1)

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

More vulnerabilities in Freerdp

CVE-2026-45700 — Critical (CVSS 9.8): FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, FreeRDP's planar bitmap decoder has…
CVE-2026-31806 — Critical (CVSS 9.8): FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, the gdi_surface_bits() function…
CVE-2026-25997 — Critical (CVSS 9.8): FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `xf_clipboard_format_equal`…
CVE-2026-25959 — Critical (CVSS 9.8): FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `xf_cliprdr_provide_data_`…
CVE-2026-25955 — Critical (CVSS 9.8): FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0,…
CVE-2026-25953 — Critical (CVSS 9.8): FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0,…

All CVEs affecting Freerdp →

Other CWE-617 (Reachable Assertion) vulnerabilities

CVE-2020-3615 — Critical (CVSS 9.8): Valid deauth/disassoc frames is dropped in case if RMF is enabled and some rouge peer keep on sending rogue…
CVE-2019-9795 — Critical (CVSS 9.8): A vulnerability where type-confusion in the IonMonkey just-in-time (JIT) compiler could potentially be used by…
CVE-2026-31739 — High (CVSS 8.8): In the Linux kernel, the following vulnerability has been resolved: crypto: tegra - Add missing CRYPTO_ALG_ASYNC The…
CVE-2020-12417 — High (CVSS 8.8): Due to confusion about ValueTags on JavaScript Objects, an object may pass through the type barrier, resulting in…
CVE-2020-6623 — High (CVSS 8.8): stb stb_truetype.h through 1.22 has an assertion failure in stbtt__cff_get_index.
CVE-2020-6619 — High (CVSS 8.8): stb stb_truetype.h through 1.22 has an assertion failure in stbtt__buf_seek.

Browse all CWE-617 (Reachable Assertion) vulnerabilities →