CVE-2021-40978
The mkdocs 1.2.2 built-in dev-server allows directory traversal using the port 8000, enabling remote exploitation to obtain :sensitive information.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 15.1%, higher than 97% of all known CVEs. Patch or mitigate before the next change window.
Description
The mkdocs 1.2.2 built-in dev-server allows directory traversal using the port 8000, enabling remote exploitation to obtain :sensitive information. NOTE: the vendor has disputed this as described in https://github.com/mkdocs/mkdocs/issues/2601.] and https://github.com/nisdn/CVE-2021-40978/issues/1
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 15.10% probability · 97th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-22
- Affected
- mkdocs/mkdocs
- Source
- cve@mitre.org
EPSS 15.1% since 3 November 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/mkdocs/mkdocsThird Party Advisory
- https://github.com/mkdocs/mkdocs/issues/2601Issue Tracking, Third Party Advisory
- https://github.com/nisdn/CVE-2021-40978Exploit, Third Party Advisory
- https://github.com/nisdn/CVE-2021-40978/issues/1Issue Tracking, Third Party Advisory
- https://github.com/mkdocs/mkdocsThird Party Advisory
- https://github.com/mkdocs/mkdocs/issues/2601Issue Tracking, Third Party Advisory
- https://github.com/nisdn/CVE-2021-40978Exploit, Third Party Advisory
- https://github.com/nisdn/CVE-2021-40978/issues/1Issue Tracking, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.