CVE-2025-23207: KaTeX is a fast, easy-to-use JavaScript library for TeX math rendering on the web

Routine

MEDIUM 6.3UPGRADE

CVE-2025-23207 is a medium-severity flaw (CVSS 6.3) affecting katex. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

KaTeX is a fast, easy-to-use JavaScript library for TeX math rendering on the web. KaTeX users who render untrusted mathematical expressions with `renderToString` could encounter malicious input using `\htmlData` that runs arbitrary JavaScript, or generate invalid HTML. Users are advised to upgrade to KaTeX v0.16.21 to remove this vulnerability. Users unable to upgrade should avoid use of or turn off the `trust` option, or set it to forbid `\html

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 65%)
CISA exploited list	No
Weakness	CWE-116, CWE-79
Published	2025-01-17
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: katex

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

Am I affected?

Timeline

2025-01-17 22:15 UTCPublished CVE record published
2026-06-17 08:52 UTCUpdated Record last modified

katex katex UPGRADE

Affected: >= 0.12.0 and < 0.16.21

Fixed in: 0.16.21

Safe to downgrade to: a release before 0.12.0

1. Check installed version

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

2. UPGRADE to 0.16.21 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade katex

Note

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

3. If no update is available yet, DOWNGRADE to a release before 0.12.0 (Debian / Ubuntu)

apt-cache madison katex sudo apt install katex=<VERSION_BEFORE_0.12.0> sudo apt-mark hold katex

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list katex sudo dnf downgrade katex-<VERSION_BEFORE_0.12.0> sudo dnf versionlock add katex

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2025-23207?

katex: upgrade to 0.16.21. Exact commands for each OS are on this page.

Is CVE-2025-23207 being exploited?

CVE-2025-23207 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-2025-23207 affect?

CVE-2025-23207 affects katex. Severity is medium (CVSS 6.3). KaTeX is a fast, easy-to-use JavaScript library for TeX math rendering on the web. KaTeX users who render untrusted mathematical expressions with `renderToString` could encounter malicious input using `\htmlData` that runs arbitrary JavaScr

How urgent is CVE-2025-23207?

Priority 31/100. No elevated risk signals yet.

References

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