CVE-2025-7207VulnerabilityPublished 9 Jul 2025

CVE-2025-7207: mruby · Heap-based Buffer Overflow

Affects mrubySource CVE Database V5

Not known to be exploited · CVSS 4.8 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score

4.8Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 17% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Base metrics

Attack Vector: Local
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: None
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: Local: The vulnerable system is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or through terminal emulation (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., using social engineering techniques to trick a legitimate user into opening a malicious document).
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: 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.
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 9 Jul 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 2026-10-25.

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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC 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
GitHubmruby/mruby`pkg:github/mruby/mruby`Other threats	Affected =3.4.0-rc1 =3.4.0-rc2	Fixed in–

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AI-suggested

European organizations should prioritize applying the official patch identified by commit 1fdd96104180cc0fb5d3cb086b05ab6458911bb9 to all affected mruby versions (3.4.0-rc1 and 3.4.0-rc2). Beyond patching, organizations should conduct an inventory of all software and embedded systems using mruby to assess exposure. Implement strict local access controls and monitoring to prevent unauthorized local access, including enforcing least privilege principles and using endpoint detection and response (EDR) solutions to detect anomalous behavior indicative of exploitation attempts. For embedded or IoT devices, ensure secure firmware update mechanisms are in place to deploy patches promptly. Additionally, code audits and static analysis of custom applications embedding mruby can help identify potential misuse or unsafe memory operations that could exacerbate the vulnerability. Finally, organizations should maintain robust incident response plans to quickly address any exploitation attempts.

Description

A vulnerability, which was classified as problematic, was found in mruby up to 3.4.0-rc2. Affected is the function scope_new of the file mrbgems/mruby-compiler/core/codegen.c of the component nregs Handler. The manipulation leads to heap-based buffer overflow. An attack has to be approached locally. The exploit has been disclosed to the public and may be used. The name of the patch is 1fdd96104180cc0fb5d3cb086b05ab6458911bb9. It is recommended to apply a patch to fix this issue.

Impact

For European organizations, the impact of CVE-2025-7207 depends largely on the extent to which mruby is embedded in their software infrastructure. Organizations using mruby in development environments, embedded systems, or IoT devices may face risks of local privilege escalation or arbitrary code execution if attackers gain local access. This could lead to unauthorized control over affected systems, potentially compromising sensitive data or disrupting operations. The medium severity rating and local attack vector limit the scope of impact, but in environments where mruby is used in critical systems or where local access controls are weak, the threat could be more pronounced. Industries such as manufacturing, telecommunications, and critical infrastructure that utilize embedded systems with mruby scripting might be particularly vulnerable. Additionally, the lack of user interaction requirement means automated local attacks or insider threats could exploit this vulnerability. However, since no remote exploitation is possible, the risk to perimeter security is limited.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 9 Jul 2025, 00:39 UTC

Technical details

References

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