CVE-2025-67873VulnerabilityPublished 17 Dec 2025

CVE-2025-67873: capstone · Heap-based Buffer Overflow

Affects capstoneSource CVE Database V5

Not known to be exploited · CVSS 4.8 Medium.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 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 14% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: Required
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: Low

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

Attack Vector: Local: The vulnerable component 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 remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
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 impacted component.
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 on the impacted component.
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 impacted component 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 impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 17 Dec 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 2026-10-26.

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
GitHubcapstone-engine/capstone`pkg:github/capstone-engine/capstone`Other threats	Affected =6.0.0-Alpha5	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

1. Upgrade capstone to a version later than 6.0.0-Alpha5 that includes the fix from commit cbef767ab33b82166d263895f24084b75b316df3. 2. If upgrading is not immediately possible, apply the patch manually to enforce bounds checking on skipdata length in the skipdata callback. 3. Restrict local access to systems running capstone-based tools to trusted users only, minimizing the risk of exploitation by unprivileged users. 4. Implement strict user account controls and monitor for unusual user activity that might indicate attempts to exploit the vulnerability. 5. Employ application whitelisting and integrity monitoring on security analysis tools to detect unauthorized modifications or crashes. 6. Conduct regular security audits of software dependencies, especially those used in critical analysis workflows, to ensure timely patching of vulnerabilities. 7. Educate security analysts and developers about the risks of using vulnerable versions and encourage best practices in handling third-party libraries. 8. Consider sandboxing or isolating disassembly processes to limit the impact of potential memory corruption.

Description

Capstone is a disassembly framework. In versions 6.0.0-Alpha5 and prior, Skipdata length is not bounds-checked, so a user-provided skipdata callback can make cs_disasm/cs_disasm_iter memcpy more than 24 bytes into cs_insn.bytes, causing a heap buffer overflow in the disassembly path. Commit cbef767ab33b82166d263895f24084b75b316df3 fixes the issue.

Impact

For European organizations, the impact of CVE-2025-67873 depends largely on the deployment of capstone within their security infrastructure. Organizations involved in cybersecurity research, malware analysis, reverse engineering, or software development that utilize capstone could face risks of system crashes, data corruption, or potential privilege escalation if the vulnerability is exploited. The heap overflow could allow attackers to execute arbitrary code or disrupt disassembly processes, undermining the integrity and availability of critical analysis tools. This may lead to delays in threat detection or forensic investigations. Although exploitation requires local access and user interaction, insider threats or compromised user accounts could facilitate attacks. The confidentiality of sensitive analysis data might also be at risk if memory corruption leads to information leakage. Given the medium CVSS score and the requirement for local access, the threat is moderate but should not be underestimated in high-security environments. Failure to patch could expose organizations to targeted attacks aiming to disable or manipulate security tooling, which is particularly concerning for critical infrastructure operators and government agencies in Europe.

CWE-122Heap-based Buffer Overflow (opens in a new tab)
Variant weaknessLikelihood of exploit: HighCWE Top 25 (2025): #16
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
Pre-design: Use a language or compiler that performs automatic bounds checking.
Architecture and Design
Use an abstraction library to abstract away risky APIs. Not a complete solution.
Operation · Build and Compilation · Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Forced Integer Overflow (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 24 Dec 2025, 21:51 UTC

WeaknessesCWE-122

Technical details

References

Community reviews

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