Regular expression Denial of Service in @progfay/scrapbox-parser

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

4.3 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

EPSS

• CVE-2021-27405: 1.76% estimated exploitation activity in the next 30 days; percentile 78.00 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact A Regular expression Denial of Service flaw was found in the @progfay/scrapbox-parser package before 6.0.3, 7.0.2 for Node.js. The attacker that is able to be parsed a specially crafted text may cause the application to consume an excessive amount of CPU. Patches Upgrade to version 6.0.3, 7.0.2 or later. Workarounds Avoid to parse text with a lot of chars. References https://github.com/progfay/scrapbox-parser/pull/519 https://github.com/progfay/scrapbox-parser/pull/539 https://github.com/progfay/scrapbox-parser/pull/540 https://cve.mitre.org/cgi-bin/cvename.cgi?name=2021-27405 https://snyk.io/vuln/SNYK-JS-PROGFAYSCRAPBOXPARSER-1076803 For more information If you have any questions or comments about this advisory: Open an issue in github.com/progfay/scrapbox-parser

Published by the source

1 Mar 2021, 20:44 UTC

Last modified by the source

8 Nov 2023, 04:05 UTC

Source last checked

26 Oct 2026, 12:20 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-9fhw-r42p-5c7r

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-9fhw-r42p-5c7r

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# Patch Next advisory brief: CVE-2021-27405

Advisory: Regular expression Denial of Service in @progfay/scrapbox-parser
IDs: CVE-2021-27405, GHSA-9fhw-r42p-5c7r
Record: https://patchnext.com/advisories/cve-2021-27405 (revision 2, source checked 26 Oct 2026, 12:20 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @progfay/scrapbox-parser 7.0.2, 6.0.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @progfay/scrapbox-parser: affected < 6.0.3; >= 7.0.0, < 7.0.2; fixed in 6.0.3, 7.0.2

## Suggested inspection (read-only)
- `npm ls @progfay/scrapbox-parser --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @progfay/scrapbox-parser.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-9fhw-r42p-5c7r (OSV record GHSA-9fhw-r42p-5c7r lists affected ranges: npm @progfay/scrapbox-parser >=0 =7.0.0 <7.0.2 (fixed))
- Verified: https://github.com/advisories/GHSA-9fhw-r42p-5c7r (GitHub-reviewed advisory GHSA-9fhw-r42p-5c7r lists affected ranges: npm @progfay/scrapbox-parser >=0 =7.0.0 <7.0.2)

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