CVE-2025-57349: The messageformat package, an implementation of the Unicode MessageFormat 2 specification for JavaScript, is v

Q: How do I fix CVE-2025-57349?

messageformat: upgrade to 2.3.0. Exact commands for each OS are on this page.

Q: Is CVE-2025-57349 being exploited?

CVE-2025-57349 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2025-57349 affect?

CVE-2025-57349 affects messageformat. Severity is high (CVSS 7.5). 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 pr

Q: How urgent is CVE-2025-57349?

Priority 40/100. High severity; Remotely exploitable, no login, no user action

This month

HIGH 7.5REMOTEUPGRADE

CVE-2025-57349 is a high-severity flaw (CVSS 7.5) affecting messageformat. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 inj

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 66%)
CISA exploited list	No
Weakness	CWE-1321
Published	2025-09-24
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: openjsf

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-09-24 19:15 UTCPublished CVE record published
2026-06-17 09:43 UTCUpdated Record last modified

openjsf messageformat UPGRADE

Affected: < 2.3.0

Fixed in: 2.3.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy messageformat || rpm -q messageformat || messageformat --version

2. UPGRADE to 2.3.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade messageformat

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade messageformat

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-57349?

messageformat: upgrade to 2.3.0. Exact commands for each OS are on this page.

Is CVE-2025-57349 being exploited?

CVE-2025-57349 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-57349 affect?

CVE-2025-57349 affects messageformat. Severity is high (CVSS 7.5). 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 pr

How urgent is CVE-2025-57349?

Priority 40/100. High severity; Remotely exploitable, no login, no user action

References

← Back to latest CVEs