CVE-2021-23382 Regular Expression Denial of Service (ReDoS)

What is CVE-2021-23382?

CVE-2021-23382 is a medium-severity denial of service vulnerability in postcss, published on 26 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The package postcss before 8.2.13 are vulnerable to Regular Expression Denial of Service (ReDoS) via getAnnotationURL() and loadAnnotation() in lib/previous-map.js. The vulnerable regexes are caused mainly by the sub-pattern \/\*\s* sourceMappingURL=(.*).

Weakness: CWE-1333

Which versions are affected by CVE-2021-23382?

4 open source packages ship an affected version, including postcss. It affects 1 product.

Products include Postcss Postcss.

How do I fix CVE-2021-23382?

Upgrade postcss to a fixed version for your release line: 7.0.36 or 8.2.13.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-23382 being exploited?

There is no known exploitation of CVE-2021-23382 in the wild and no public exploit code.

Other vulnerabilities in postcss

• CVE-2026-45623 PostCSS: Arbitrary file read and information disclosure via attacker-controlled sourceMappingURL in CSS comments High 7.5
• CVE-2026-69153 PostCSS: incomplete fix of GHSA-6g55-p6wh-862q — attacker-controlled sourceMappingURL reads arbitrary .map files when `from` is unset Medium 6.3
• CVE-2023-44270 PostCSS line return parsing error Medium 5.3
• CVE-2021-23368 Regular Expression Denial of Service (ReDoS) Medium 5.3

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2021-23382, GHSA-566m-qj78-rww5, MINI-975m-2v6h-66fp, ROOT-APP-NPM-CVE-2021-23382, UBUNTU-CVE-2021-23382.