How severe is CVE-2025-57349?

CVE-2025-57349 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2025-57349 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-57349?

CVE-2025-57349 affects Openjsf Messageformat. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-57349?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-57349 have an EU (EUVD) identifier?

Yes. CVE-2025-57349 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-31065.

When was CVE-2025-57349 published?

CVE-2025-57349 was published on 2025-09-24 and last updated on 2026-06-17.

CVE-2025-57349

CVE-2025-57349 is a high-severity vulnerability in Openjsf Messageformat with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1321.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (29th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-31065
Weakness: CWE-1321
Affected product: Openjsf Messageformat
Published: 2025-09-24
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2025-57349?: 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.
How severe is CVE-2025-57349?: CVE-2025-57349 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-57349 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-57349?: CVE-2025-57349 affects Openjsf Messageformat. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-57349?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-57349 have an EU (EUVD) identifier?: Yes. CVE-2025-57349 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-31065.
When was CVE-2025-57349 published?: CVE-2025-57349 was published on 2025-09-24 and last updated on 2026-06-17.

References

https://github.com/messageformat/messageformat/issues/452

Affected products (1)

cpe:2.3:a:openjsf:messageformat:*:*:*:*:*:*:*:*

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