CVE-2020-26307 json
GHSL-2020-301: Regular Expression Denial of Service (ReDoS) in HTML2Markdown
published 2024-10-26 2 y ago modified 2026-06-17 4 mo ago also EUVD-2020-18858
- cvss
- 8.7
- version 4.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 35%
- public exploits
- 0
- none known
Summary
HTML2Markdown is a Javascript implementation for converting HTML to Markdown text. All available versions contain one or more regular expressions that are vulnerable to Regular Expression Denial of Service (ReDoS). As of time of publication, no known patches are available.
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 2 y ago
Exploit prediction
0.41% chance of exploitation in the next 30 days, higher than 35% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/U:Green |
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Green |
Affected products
- kates html2markdown
Classification
- Weakness
-
- CWE-1333 Inefficient Regular Expression Complexity
References
Sources
- CVE List CVE-2020-26307
- NVD CVE-2020-26307
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.