VulnerabilityPublished 6 Mar 2026Updated 12 Mar 2026

CVE-2025-69653: quickjs · Reachable Assertion

Affects quickjsSource CVE Database V5

Not known to be exploited · CVSS 6.5 Medium.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

6.5Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

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

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, 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: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
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: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Mar 2026
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 26 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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
GitHubbellard/quickjs`pkg:github/bellard/quickjs`Other threats	Affected =2025-09-13	Fixed in–

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

AI-suggested

To mitigate CVE-2025-69653, organizations should promptly update QuickJS to the patched version released after 2025-12-11, which includes the fix in commit 1dbba8a88eaa40d15a8a9b70bb1a0b8fb5b552e6. Until patching is possible, restrict or sanitize JavaScript inputs processed by the qjs interpreter, especially when using the -m option. Implement input validation and filtering to detect and block suspicious or malformed scripts that could trigger the assertion failure. Limit the use of the -m option if it is not essential, as the vulnerability is specifically triggered in this mode. Employ runtime monitoring to detect interpreter crashes and automate recovery procedures to minimize downtime. For embedded or IoT devices, ensure secure update mechanisms are in place to deploy patches rapidly. Additionally, isolate QuickJS execution environments to contain potential DoS impacts and prevent cascading failures in dependent systems.

Description

A crafted JavaScript input can trigger an internal assertion failure in QuickJS release 2025-09-13, fixed in commit 1dbba8a88eaa40d15a8a9b70bb1a0b8fb5b552e6 (2025-12-11), in file gc_decref_child in quickjs.c, when executed with the qjs interpreter using the -m option. This leads to an abort (SIGABRT) during garbage collection and causes a denial-of-service.

Impact

The primary impact of CVE-2025-69653 is denial-of-service, where the QuickJS interpreter crashes unexpectedly during garbage collection when processing malicious JavaScript input. This can disrupt applications or services embedding QuickJS or using it as a scripting engine, potentially causing downtime or degraded service availability. Since QuickJS is often used in embedded systems, IoT devices, and lightweight scripting environments, affected devices may become unresponsive or require manual restart. There is no direct impact on data confidentiality or integrity, but service interruptions could affect business operations, especially in environments relying on automated scripting or real-time processing. The requirement for user interaction and script execution limits remote exploitation but does not eliminate risk in scenarios where untrusted scripts are processed. Organizations embedding QuickJS in products or development tools should consider the risk of DoS attacks that could be triggered by malicious inputs, especially in exposed or multi-tenant environments.

CWE-617Reachable Assertion (opens in a new tab)
Base weakness
The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.
Implementation
Make sensitive open/close operation non reachable by directly user-controlled data (e.g. open/close resources)
Implementation · Input Validation
Perform input validation on user data.
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/bellard/quickjs/issues/467 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 13 Mar 2026, 19:01 UTC

WeaknessesCWE-617

Technical details

References

Community reviews

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