CVE-2025-57349 json
messageformat has a prototype pollution vulnerability
published 2025-09-24 13 mo ago modified 2026-06-17 4 mo ago also GHSA-xfqm-j7pc-xrfc , EUVD-2025-31065
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 34%
- public exploits
- 0
- none known
Summary
The messageformat package, an implementation of the Unicode MessageFormat 2 specification for JavaScript, is vulnerable to prototype pollution due to improper handling of message key paths in versions prior to 2.3.0. The flaw arises when processing nested message keys containing special characters (e.g., __proto__ ), which can lead to unintended modification of the JavaScript Object prototype. This vulnerability may allow a remote attacker to inject properties into the global object prototype via specially crafted message input, potentially causing denial of service or other undefined behaviors in applications using the affected component.
Patch / fix
- npm messageformat 3.0.0-beta.0
- openjsf messageformat 2.3.0
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 13 mo ago
Exploit prediction
0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | messageformat | <3.0.0-beta.0 |
3.0.0-beta.0 |
Classification
- Weakness
-
- CWE-1321 Improperly Controlled Modification of Object Prototype Attributes
References
-
github.com
/messageformat/messageformat/issues/452
web, issue-tracking, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2025-57349
advisory
-
github.com
/messageformat/messageformat
package
Sources
- CVE List CVE-2025-57349
- GitHub Advisory GHSA-xfqm-j7pc-xrfc
- NVD CVE-2025-57349
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