VulnerabilityPublished 3 Nov 2026

CVE-2026-121387: FreeRDP · Out-of-bounds Read

Affects FreeRDPSource CVE Database V5

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Not known to be exploited · CVSS 5.3 Medium : upgrade to 3.32.2 when convenient.

Data as of 3 Nov 2026, 15:00 UTC

CVSS 4.0 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (VulnCheck)	CVSS 4.0	5.3
CNA (VulnCheck)	CVSS 3.1	4.3

Patch: Available – fixed in 3.32.2

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: Passive
Vulnerable system confidentiality: None
Vulnerable system integrity: None
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: Passive: Successful exploitation of this vulnerability requires limited interaction by the targeted user with the vulnerable system and the attacker’s payload. These interactions would be considered involuntary and do not require that the user actively subvert protections built into the vulnerable system.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 3 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade FreeRDP to 3.32.2.

Affected software

Product	Affected	Fixed in
FreeRDPFreeRDP	Affected >=2.0.0 <3.32.2	Fixed in 3.32.2

AI-suggested

Upgrade FreeRDP to version 3.32.2 or later, where this vulnerability is fixed. Until then, avoid connecting to untrusted RDP servers that might exploit this flaw.

Description

FreeRDP versions from 2.0.0 up to but not including 3.32.2 contain an out-of-bounds read vulnerability in the audio decoding function freerdp_dsp_decode_gsm610. This flaw allows malicious RDP servers to send specially crafted truncated GSM610 audio frames, causing the client to read beyond the intended audio buffer. Such malformed input can lead to client crashes. The issue is fixed in FreeRDP version 3.32.2.

Impact

An attacker controlling an RDP server can cause a FreeRDP client to perform out-of-bounds reads by sending malformed truncated GSM610 audio frames. This can lead to client crashes, resulting in denial of service for the user. There is no indication of code execution or data disclosure beyond the out-of-bounds read. No known exploits are reported in the wild.

Summary

CVE-2026-121387 is an out-of-bounds read vulnerability in FreeRDP's freerdp_dsp_decode_gsm610 function affecting versions >=2.0.0 and <3.32.2. Malicious RDP servers can exploit this by negotiating GSM610 audio on the rdpsnd channel and sending a WAVE2 message shorter than a valid 33- or 32-byte WAV49 frame. This causes the client to read past the allocated audio buffer, potentially crashing the client application. The vulnerability has a CVSS 4.0 base score of 5.3, indicating medium severity. The flaw is resolved in version 3.32.2.

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Exploitation evidence

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Affected software

Description

AI analysisMachine-generated, updated 3 Nov 2026, 15:00 UTC

Technical details

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