What is CVE-2021-38193?

CVE-2021-38193 is a medium-severity vulnerability in Ammonia Project, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-08-08.

How severe is CVE-2021-38193?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Ammonia Project

CVE-2021-38193

An issue was discovered in the ammonia crate before 3.1.0 for Rust. XSS can occur because the parsing differences for HTML, SVG, and MathML are mishandled, a similar issue to CVE-2020-26870.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-08-08 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.007 (51.7th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 51.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Ammonia Project

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

rustsec.org/advisories/RUSTSEC-2021-0074.html (Exploit, Patch, Third Party Advisory, Issue Tracking)
raw.githubusercontent.com/rustsec/advisory-db/main/crates/ammonia/RUSTSEC-2021-… (Third Party Advisory)

Frequently asked questions

What is CVE-2021-38193?: CVE-2021-38193 is a medium-severity vulnerability in Ammonia Project, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-08-08.
How severe is CVE-2021-38193?: Medium severity. CVSS v3 base score is 6.1 out of 10.