CVE-2021-40898: A Regular Expression Denial of Service (ReDOS) vulnerability was discovered in scaffold-helper v1.2.0 when cop

Q: How do I fix CVE-2021-40898?

scaffold-helper: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2021-40898 being exploited?

CVE-2021-40898 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-40898 affect?

CVE-2021-40898 affects scaffold-helper. Severity is high (CVSS 7.5). A Regular Expression Denial of Service (ReDOS) vulnerability was discovered in scaffold-helper v1.2.0 when copying crafted invalid files.

Q: How urgent is CVE-2021-40898?

Priority 52/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 7.5REMOTEDOWNGRADE

CVE-2021-40898 is a high-severity flaw (CVSS 7.5) affecting scaffold-helper. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A Regular Expression Denial of Service (ReDOS) vulnerability was discovered in scaffold-helper v1.2.0 when copying crafted invalid files.

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.1% (top 36%)
CISA exploited list	No
Weakness	CWE-1333
Published	2022-06-27
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: scaffold-helper project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2022-06-27 11:15 UTCPublished CVE record published
2026-06-17 04:07 UTCUpdated Record last modified

scaffold-helper project scaffold-helper DOWNGRADE

Affected: 1.2.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.2.0

1. Check installed version

npm ls scaffold-helper

2. No fixed release: DOWNGRADE to a release before 1.2.0

npm view scaffold-helper versions npm install scaffold-helper@"<1.2.0"

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
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-2021-40898?

scaffold-helper: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-40898 being exploited?

CVE-2021-40898 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-2021-40898 affect?

CVE-2021-40898 affects scaffold-helper. Severity is high (CVSS 7.5). A Regular Expression Denial of Service (ReDOS) vulnerability was discovered in scaffold-helper v1.2.0 when copying crafted invalid files.

How urgent is CVE-2021-40898?

Priority 52/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

References

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