PatchTheCVECVE-2021-23490: The package parse-link-header before 2.0.0 are vulnerable to Regular Expression Denial of Service (ReDoS) via
CVE-2021-23490 is a high-severity flaw (CVSS 7.5) affecting parse-link-header. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
The package parse-link-header before 2.0.0 are vulnerable to Regular Expression Denial of Service (ReDoS) via the checkHeader function.
Why this priority
- High severity
- Public exploit reference
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 7.5 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 1.9% (top 20%) |
| CISA exploited list | No |
| Weakness | CWE-1333 |
| Published | 2021-12-24 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2021-23490?
parse-link-header: upgrade to 2.0.0. Exact commands for each OS are on this page.
Is CVE-2021-23490 being exploited?
CVE-2021-23490 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2021-23490 affect?
CVE-2021-23490 affects parse-link-header. Severity is high (CVSS 7.5). The package parse-link-header before 2.0.0 are vulnerable to Regular Expression Denial of Service (ReDoS) via the checkHeader function.
How urgent is CVE-2021-23490?
Priority 56/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action