CVE-2026-1144VulnerabilityPublished 19 Jan 2026Updated 25 Feb 2026

CVE-2026-1144: quickjs · Use After Free

Affects quickjsSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score

5.3Medium

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 36% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/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: None
User Interaction: Passive
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: 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: 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 19 Jan 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 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
quickjs-ngquickjs	Affected =0.1 =0.2 =0.3 =0.4 =0.5 =0.6 =0.7 =0.8 =0.9 =0.10 =0.11.0	Fixed in–
GitHubquickjs-ng/quickjs`pkg:github/quickjs-ng/quickjs`Other threats	Affected =0.1 =0.2 =0.3 =0.4 =0.5 =0.6 =0.7 =0.8 =0.9 =0.10 =0.11.0	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-2026-1144, organizations should promptly apply the official patch identified by commit ea3e9d77454e8fc9cb3ef3c504e9c16af5a80141 to all affected versions of quickjs-ng quickjs. Where patching is not immediately feasible, consider isolating or restricting network access to systems running vulnerable versions to reduce exposure. Implement strict input validation and sandboxing for any JavaScript code executed via quickjs to limit the impact of potential exploitation. Monitor network and application logs for anomalous behavior indicative of exploitation attempts, such as unexpected crashes or suspicious JavaScript payloads. Employ runtime protections like memory safety tools or exploit mitigation techniques (e.g., ASLR, DEP) to reduce the risk of successful exploitation. For embedded devices, ensure secure firmware update mechanisms are in place to facilitate timely patch deployment. Engage in threat hunting activities focusing on indicators of compromise related to quickjs exploitation. Finally, maintain an inventory of all software components using quickjs-ng quickjs to ensure comprehensive coverage during remediation efforts.

Description

A vulnerability was detected in quickjs-ng quickjs up to 0.11.0. Affected is an unknown function of the file quickjs.c of the component Atomics Ops Handler. The manipulation results in use after free. The attack can be executed remotely. The exploit is now public and may be used. The patch is identified as ea3e9d77454e8fc9cb3ef3c504e9c16af5a80141. Applying a patch is advised to resolve this issue.

Impact

The vulnerability poses a moderate risk to organizations using quickjs-ng quickjs, especially those embedding it in IoT devices, edge computing platforms, or software products that execute JavaScript code. Successful exploitation could allow remote attackers to execute arbitrary code, crash applications, or manipulate memory, potentially leading to data leakage or service disruption. This can affect confidentiality, integrity, and availability of affected systems. Given the public availability of an exploit, attackers may attempt to leverage this vulnerability in targeted or opportunistic attacks. Organizations in sectors relying heavily on embedded systems, such as telecommunications, industrial control, consumer electronics, and automotive, may face increased risks. The medium severity score reflects the balance between ease of exploitation and limited impact scope, but the presence of a public exploit elevates the threat level. Failure to patch could result in compromise of devices or software, leading to broader network infiltration or operational disruptions.

Summary

CVE-2026-1144 identifies a use-after-free vulnerability in the quickjs-ng quickjs JavaScript engine, versions 0.1 through 0.11.0. The vulnerability resides in an unspecified function within the Atomics Ops Handler component of quickjs.c. Use-after-free bugs occur when a program continues to use memory after it has been freed, leading to undefined behavior such as memory corruption, crashes, or potential code execution. This particular flaw can be triggered remotely without requiring authentication, although it does require user interaction, such as processing crafted JavaScript code. The vulnerability impacts confidentiality, integrity, and availability, but with limited scope and impact severity. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:P), and low impact on confidentiality, integrity, and availability (VC:L, VI:L, VA:L). A public exploit is available, increasing the urgency for remediation. The patch identified by commit ea3e9d77454e8fc9cb3ef3c504e9c16af5a80141 addresses the issue. Quickjs-ng quickjs is a lightweight JavaScript engine often embedded in IoT devices, applications, and other software requiring JavaScript execution capabilities. The vulnerability's exploitation could lead to arbitrary code execution or denial of service, depending on the attacker's payload and environment.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 3 Mar 2026, 01:17 UTC

Technical details

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