CVE-2026-59887: CWE-407: Inefficient Algorithmic Complexity in markdown-it linkify-it
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.
AI Analysis
Technical Summary
The vulnerability in linkify-it (a link recognition library with full Unicode support) involves the mailto: schema validator used by the .test() and .match() functions. Before version 5.0.2, each mailto: occurrence triggers scanning of the remaining input via src_email_name in lib/re.mjs, resulting in O(n^2) CPU usage on crafted user text. This inefficient algorithmic complexity can cause high CPU consumption, potentially leading to denial of service conditions. The fix was implemented in version 5.0.2.
Potential Impact
The vulnerability causes high CPU consumption (denial of service) when processing crafted input containing multiple mailto: links. There is no impact on confidentiality or integrity, but availability can be severely affected due to resource exhaustion.
Mitigation Recommendations
Upgrade to linkify-it version 5.0.2 or later, where this issue is fixed. Patch status is confirmed by the version fix noted in the description. No other mitigations are specified.
CVE-2026-59887: CWE-407: Inefficient Algorithmic Complexity in markdown-it linkify-it
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.
CVSS v3.1
Score 7.5high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in linkify-it (a link recognition library with full Unicode support) involves the mailto: schema validator used by the .test() and .match() functions. Before version 5.0.2, each mailto: occurrence triggers scanning of the remaining input via src_email_name in lib/re.mjs, resulting in O(n^2) CPU usage on crafted user text. This inefficient algorithmic complexity can cause high CPU consumption, potentially leading to denial of service conditions. The fix was implemented in version 5.0.2.
Potential Impact
The vulnerability causes high CPU consumption (denial of service) when processing crafted input containing multiple mailto: links. There is no impact on confidentiality or integrity, but availability can be severely affected due to resource exhaustion.
Mitigation Recommendations
Upgrade to linkify-it version 5.0.2 or later, where this issue is fixed. Patch status is confirmed by the version fix noted in the description. No other mitigations are specified.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-07-07T16:40:07.983Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4e7ad4c9d9e3dbe36a7d63
Added to database: 07/08/2026, 16:29:08 UTC
Last enriched: 07/16/2026, 10:07:03 UTC
Last updated: 08/22/2026, 15:35:30 UTC
Views: 101
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