CVE-2021-23368

Regular Expression Denial of Service (ReDoS)

5.3 MediumFix available

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: Low

Exploit likelihood

3.51%Up 2.2 points since Apr 14, 2021

What each source reports

CVE List Score used 5.3

Regular Expression Denial of Service (ReDoS)

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.

Record: CVE-2021-23368
CVSS 3.1: 5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Updated: 2026-11-02

EUVDEUVD-2021-1108 5.3

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.

Record: EUVD-2021-1108
CVSS 3.1: 5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Updated: 2026-11-03

GitHub AdvisoriesGHSA-hwj9-h5mp-3pm3 5.3

Regular Expression Denial of Service in postcss

The npm package postcss from 7.0.0 and before versions 7.0.36 and 8.2.10 is vulnerable to Regular Expression Denial of Service (ReDoS) during source map parsing.

Record: GHSA-hwj9-h5mp-3pm3
CVSS 3.1: 5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness: CWE-400
Updated: 2026-11-02

NVD 5.3

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.

Record: CVE-2021-23368
CVSS 3.1: 5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS 2.0: 5.0 MediumAV:N/AC:L/Au:N/C:N/I:N/A:P
Updated: 2026-11-02

OSV 5.3

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.

Record: CVE-2021-23368
CVSS 3.1: 5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Updated: 2026-11-02

OSVDEBIAN-CVE-2021-23368 5.3

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.

Record: DEBIAN-CVE-2021-23368
CVSS 3.1: 5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Updated: 2026-11-02

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OSVGHSA-hwj9-h5mp-3pm3 5.3

Regular Expression Denial of Service in postcss

The npm package postcss from 7.0.0 and before versions 7.0.36 and 8.2.10 is vulnerable to Regular Expression Denial of Service (ReDoS) during source map parsing.

Record: GHSA-hwj9-h5mp-3pm3
CVSS 3.1: 5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness: CWE-400
Updated: 2026-11-02

OSVUBUNTU-CVE-2021-23368 5.3

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.

Record: UBUNTU-CVE-2021-23368
CVSS 3.1: 5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Updated: 2026-11-02

OSVCLSA-2026-1776299672 No score

TuxCare security update for postcss (3 CVEs)

TuxCare rebuilt postcss to address 3 CVEs. Fixed in 7.0.14-tuxcare.1.

Record: CLSA-2026-1776299672
Updated: 2026-11-02

OSVCLSA-2026-1779065198 No score

TuxCare security update for postcss (4 CVEs)

TuxCare rebuilt postcss to address 4 CVEs. Fixed in 7.0.21-tuxcare.1.

Record: CLSA-2026-1779065198
Updated: 2026-11-02

OSVCLSA-2026-1779324473 No score

TuxCare security update for postcss (4 CVEs)

TuxCare rebuilt postcss to address 4 CVEs. Fixed in 7.0.32-tuxcare.1.

Record: CLSA-2026-1779324473
Updated: 2026-11-02

OSVCLSA-2026-1779670117 No score

TuxCare security update for postcss (4 CVEs)

TuxCare rebuilt postcss to address 4 CVEs. Fixed in 7.0.17-tuxcare.1.

Record: CLSA-2026-1779670117
Updated: 2026-11-02

OSVCLSA-2026-1792164471 No score

TuxCare security update for postcss (3 CVEs)

TuxCare rebuilt postcss to address 3 CVEs. Fixed in 8.2.9-tuxcare.1.

Record: CLSA-2026-1792164471
Updated: 2026-11-02

OSVROOT-APP-NPM-CVE-2021-23368 No score

CVE-2021-23368 in postcss - Patched by Root

Root has patched CVE-2021-23368 in the postcss package for Root:npm. Multiple fixed versions available.

Record: ROOT-APP-NPM-CVE-2021-23368
Updated: 2026-11-02

Affected products

postcss

Affected packages

Affected packages
Package	Affected	Fixed
`postcss` npm	7.0.0 up to 7.0.36	7.0.36
`postcss` npm	8.0.0 up to 8.2.10	8.2.10
`postcss` TuxCare:npm From an advisory covering 3 CVEs	7.0.14-tuxcare.0 up to 7.0.14-tuxcare.1, plus listed versions 7.0.14	7.0.14-tuxcare.1
`postcss` TuxCare:npm From an advisory covering 4 CVEs	7.0.21-tuxcare.0 up to 7.0.21-tuxcare.1, plus listed versions 7.0.21	7.0.21-tuxcare.1
`postcss` TuxCare:npm From an advisory covering 4 CVEs	7.0.32-tuxcare.0 up to 7.0.32-tuxcare.1, plus listed versions 7.0.32	7.0.32-tuxcare.1
`postcss` TuxCare:npm From an advisory covering 4 CVEs	7.0.17-tuxcare.0 up to 7.0.17-tuxcare.1, plus listed versions 7.0.17	7.0.17-tuxcare.1
`postcss` TuxCare:npm From an advisory covering 3 CVEs	8.2.9-tuxcare.0 up to 8.2.9-tuxcare.1, plus listed versions 8.2.9	8.2.9-tuxcare.1
`node-postcss` Debian:12	before 8.2.1+~cs5.3.23-6	8.2.1+~cs5.3.23-6
`node-postcss` Debian:13	before 8.2.1+~cs5.3.23-6	8.2.1+~cs5.3.23-6
`node-postcss` Debian:14	before 8.2.1+~cs5.3.23-6	8.2.1+~cs5.3.23-6
`postcss` Root:npm	before 7.0.36-aikido.1	7.0.36-aikido.1
`@rootio/postcss` Root:npm	before 7.0.36-root.io.1	7.0.36-root.io.1
`node-postcss` Ubuntu:22.04:LTS	All versions, plus listed versions 8.2.1+~cs5.3.23-88.4.5+~cs7.1.51-28.4.6+~cs7.3.21-1	None known

History

History
Recorded	Changed	Sources
Nov 6, 2026	affected, facts
Nov 3, 2026	aliases, published	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-23368 is a medium vulnerability (CVSS 5.3) in Postcss, published April 12, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 3.51%, the 89th percentile. Fixed in postcss 7.0.36.

References

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