CVE-2021-23368 Regular Expression Denial of Service (ReDoS)
An attacker can cause a denial of service in applications using PostCSS by providing malicious input during source map parsing.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-23368?
CVE-2021-23368 is a medium-severity denial of service vulnerability in postcss, published on 12 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The package postcss from 7.0.0 and before 8.2.10 are vulnerable to Regular Expression Denial of Service (ReDoS) during source map parsing.
Which versions are affected by CVE-2021-23368?
4 open source packages ship an affected version, including postcss. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
postcss npm | From 7.0.0 | 7.0.36 |
postcss npm | From 7.0.0 | 7.0.36 |
postcss npm | From 8.0.0 | 8.2.10 |
postcss npm | From 8.0.0 | 8.2.10 |
Products include Postcss Postcss.
How do I fix CVE-2021-23368?
Upgrade postcss to a fixed version for your release line: 7.0.36 or 8.2.10.
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-2021-23368 being exploited?
There is no known exploitation of CVE-2021-23368 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
- CVE-2026-69153 PostCSS: incomplete fix of GHSA-6g55-p6wh-862q — attacker-controlled sourceMappingURL reads arbitrary .map files when `from` is unset
- CVE-2023-44270 PostCSS line return parsing error
- CVE-2021-23382 Regular Expression Denial of Service (ReDoS)
Sources
Also known as DEBIAN-CVE-2021-23368, GHSA-hwj9-h5mp-3pm3, MINI-cprp-rg48-rhhp, ROOT-APP-NPM-CVE-2021-23368, UBUNTU-CVE-2021-23368.