CVE-2023-49550Public exploitNetwork attack vector

Interpreter crash via malformed JavaScript memory write

Published Jan 2, 2024 · Updated May 16, 2025

Memory-safety failure in Cesanta mjs 2.20.0 allows remote attackers to crash the interpreter by supplying crafted JavaScript. The published proof of concept makes the standalone interpreter process JSON.parse and JSON.stringify calls amid malformed syntax, after which AddressSanitizer records an invalid write and segmentation fault at mjs+0x4ec508; the responsible function is undisclosed. Unauthenticated delivery of attacker-controlled JavaScript to an embedding application's mjs execution path is required, and successful exploitation terminates the mjs process without reported data disclosure or modification.

CVSS severity7.5
High
EPSS probability0.76%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Memory-safety failure in Cesanta mjs 2.20.0 allows remote attackers to crash the interpreter by supplying crafted JavaScript. The published proof of concept makes the standalone interpreter process JSON.parse and JSON.stringify calls amid malformed syntax, after which AddressSanitizer records an invalid write and segmentation fault at mjs+0x4ec508; the responsible function is undisclosed. Unauthenticated delivery of attacker-controlled JavaScript to an embedding application's mjs execution path is required, and successful exploitation terminates the mjs process without reported data disclosure or modification.

The record

CVE
CVE-2023-49550
Published
Jan 2, 2024
Updated
May 16, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-400, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 2, 2024CVE publishedPublication date reported by the CVE source.
  2. May 16, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo