CVE-2020-26307
GHSL-2020-301: Regular Expression Denial of Service (ReDoS) in HTML2Markdown
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
GHSL-2020-301: Regular Expression Denial of Service (ReDoS) in HTML2Markdown
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.
- Record
CVE-2020-26307- CVSS 4.0
- 8.7 High
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 - Weakness
- CWE-1333
- Updated
- 2026-11-02
EUVDEUVD-2020-18858
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.
- Record
EUVD-2020-18858- CVSS 4.0
- 8.7 High
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 - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-qmpf-c66x-m579
HTML2Markdown is a Javascript implementation for converting HTML to Markdown text. All available...
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.
- Record
GHSA-qmpf-c66x-m579- CVSS 4.0
- 8.7 High
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 - Weakness
- CWE-1333
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2020-26307- CVSS 4.0
- 8.7 High
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 - Weakness
- CWE-1333
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | ||
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-26307 is a high vulnerability (CVSS 8.7) in Kates Html2markdown, published October 26, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.41%, the 35th percentile. No source names a fixed version.