# CVE-2026-59887: linkify-it: Quadratic-complexity DoS via the `mailto:` validator scan-loop on attacker text

> CVE-2026-59887: linkify-it: Quadratic-complexity DoS via the `mailto:` validator scan-loop on attacker text. CVSS 7.5 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-59887
Last updated: 2026-10-25T17:10:00Z

- Published: 2026-07-08 15:58 UTC · Updated: 2026-10-25 17:10 UTC · Assigner: GitHub\_M
- CVSS: 7.5 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS: 0.64%, 51th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-407

## Description

linkify-it is a links recognition library with full Unicode support. Prior to 5.0.2, the mailto: schema validator used by .test() and .match() can be invoked at every mailto: occurrence and scan the remaining input through src\_email\_name in lib/re.mjs, causing O(n^2) CPU consumption on crafted user text. This issue is fixed in version 5.0.2.

## Affected vendors and products

- markdown-it: linkify-it

## Tracked companies

- [Confluence](https://rewindex.com/company/confluence.md)
- [Jira](https://rewindex.com/company/jira.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-59887)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-59887)
- [https://github.com/markdown-it/linkify-it/commit/105e5d77f7d119871d2b2d86ed208568eb3e7ffe](https://github.com/markdown-it/linkify-it/commit/105e5d77f7d119871d2b2d86ed208568eb3e7ffe)
- [https://github.com/markdown-it/linkify-it/releases/tag/5.0.2](https://github.com/markdown-it/linkify-it/releases/tag/5.0.2)
- [https://github.com/markdown-it/linkify-it/security/advisories/GHSA-v245-v573-v5vm](https://github.com/markdown-it/linkify-it/security/advisories/GHSA-v245-v573-v5vm)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-59887 · Markdown: https://rewindex.com/cve/CVE-2026-59887.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-59887 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:13:27.461Z