VulnerabilityPublished 15 Mar 2026Updated 17 Mar 2026

CVE-2026-4185: GPAC · Stack-based Buffer Overflow

Affects GPACSource CVE Database V5

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Public exploit available · CVSS 5.3 Medium.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 4.0 base score

5.3Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 18% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Base metrics

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

Threat metrics

Exploit Maturity: POC

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: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to 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.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CVSS exploit maturity: proof of concept public
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), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 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

Affected software

Product	Affected	Fixed in
GPAC	Affected =2.5-DEV-rev2167-gcc9d617c0-master	Fixed in–

CPE configurations (1)

cpe:2.3:a:gpac:gpac:*:*:*:*:*:*:*:*

AI-suggested

To mitigate CVE-2026-4185, organizations should immediately apply the official patch identified by commit 8961c74f87ae3fe2d3352e622f7730ca96d50cf1 to all affected GPAC installations. If patching is not immediately possible, consider isolating GPAC services from untrusted networks to reduce exposure to remote attacks. Implement network-level controls such as firewalls and intrusion prevention systems to detect and block exploit attempts targeting the swf_def_bits_jpeg function. Conduct thorough code reviews and fuzz testing on multimedia processing components to identify similar vulnerabilities proactively. Monitor security advisories and threat intelligence feeds for updates on exploit activity related to this CVE. Additionally, employ application-level sandboxing or containerization to limit the impact of potential exploitation. Maintain regular backups and incident response plans to recover quickly from any successful attacks.

Description

CVE-2026-4185 is a stack-based buffer overflow vulnerability in the GPAC multimedia framework, specifically in the swf_def_bits_jpeg function of the MP4Box component. The flaw arises from improper handling of the szName argument, allowing an attacker to overflow the stack. This vulnerability can be exploited remotely without user interaction or elevated privileges. Although the CVSS score is medium (5.3), exploitation could lead to code execution or application crashes. A public exploit exists, but no widespread exploitation has been reported yet. The issue affects GPAC versions up to 2.5-DEV-rev2167-gcc9d617c0-master. Applying the available patch is strongly recommended to mitigate the risk. Organizations using GPAC for multimedia processing should prioritize updating to a fixed version to prevent potential compromise.

Impact

The exploitation of CVE-2026-4185 can have several impacts on organizations using GPAC for multimedia processing. Successful exploitation could allow remote attackers to execute arbitrary code within the context of the vulnerable application, potentially leading to full system compromise if the application runs with elevated privileges. Even if code execution is not achieved, the buffer overflow can cause application crashes, resulting in denial of service and disruption of multimedia services. Organizations relying on GPAC for media packaging, streaming, or processing may face service interruptions or data integrity issues. The presence of a public exploit increases the likelihood of attacks, especially against exposed systems. Given GPAC's use in various industries including media, broadcasting, and embedded systems, the impact could extend to critical infrastructure and commercial services. Failure to patch this vulnerability could lead to unauthorized access, data breaches, or operational downtime.

References

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