XSS in Dart SDK

published 2021-04-22 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-9681

cvss: 6.1; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.7%; EPSS 0.7% chance of exploitation in 30 days, percentile 52%
public exploits: 0; none known

Bad validation logic in the Dart SDK versions prior to 2.12.3 allow an attacker to use an XSS attack via DOM clobbering. The validation logic in dart:html for creating DOM nodes from text did not sanitize properly when it came across template tags.

Patch / fix

fixed in 1 distros 1 links 1

Google LLC Dart SDK 2.12.3

dart Arch Linux 2.12.3-1

arch linux advisories AVG-1859

github.com/dart-lang/sdk@ce5a1c2 commit

Exploit prediction

0.68% chance of exploitation in the next 30 days, higher than 52% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:N/I:P/A:N

Affected products

Google LLC Dart SDK

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

github.com /dart-lang/sdk/commit/ce5a1c2392debce967415d4c09359ff2555e3588
patch, third-party-advisory
github.com /dart-lang/sdk/security/advisories/GHSA-3rfv-4jvg-9522
broken-link

Sources

CVE List CVE-2021-22540
NVD CVE-2021-22540

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary