CVE-2022-31103: lettersanitizer is a DOM-based HTML email sanitizer for in-browser email rendering

This month

HIGH 7.5REMOTEUPGRADE

CVE-2022-31103 is a high-severity flaw (CVSS 7.5) affecting lettersanitizer. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

lettersanitizer is a DOM-based HTML email sanitizer for in-browser email rendering. All versions of lettersanitizer below 1.0.2 are affected by a denial of service issue when processing a CSS at-rule `@keyframes`. This package is depended on by [react-letter](https://github.com/mat-sz/react-letter), therefore everyone using react-letter is also at risk. The problem has been patched in version 1.0.2.

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	1.5% (top 25%)
CISA exploited list	No
Weakness	CWE-754
Published	2022-06-27
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: lettersanitizer project

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

Am I affected?

Timeline

2022-06-27 23:15 UTCPublished CVE record published
2026-06-17 04:44 UTCUpdated Record last modified

lettersanitizer project lettersanitizer UPGRADE

Affected: < 1.0.2

Fixed in: 1.0.2

Safe to downgrade to: no unaffected older release

1. Check installed version

npm ls lettersanitizer

2. UPGRADE to 1.0.2

npm install lettersanitizer@">=1.0.2"

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-2022-31103?

lettersanitizer: upgrade to 1.0.2. Exact commands for each OS are on this page.

Is CVE-2022-31103 being exploited?

CVE-2022-31103 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-2022-31103 affect?

CVE-2022-31103 affects lettersanitizer. Severity is high (CVSS 7.5). lettersanitizer is a DOM-based HTML email sanitizer for in-browser email rendering. All versions of lettersanitizer below 1.0.2 are affected by a denial of service issue when processing a CSS at-rule `@keyframes`. This package is depended o

How urgent is CVE-2022-31103?

Priority 50/100. High severity; Remotely exploitable, no login, no user action

Software pages

React vulnerabilities · GitHub vulnerabilities

References

← Back to latest CVEs