CVE-2021-27671
XSS can occur because the protection mechanism for data: and javascript: URIs is case-sensitive, allowing (for example) Data: to be used in an attack.
Does this matter?
Lower severity and a low EPSS score (0.69%). Track it; it rarely justifies an emergency change on its own.
Description
An issue was discovered in the comrak crate before 0.9.1 for Rust. XSS can occur because the protection mechanism for data: and javascript: URIs is case-sensitive, allowing (for example) Data: to be used in an attack.
- CVSS 3.1
- 6.1 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 0.69% probability · 52th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Affected
- comrak project/comrak
- Source
- cve@mitre.org
EPSS 0.7% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://rustsec.org/advisories/RUSTSEC-2021-0026.htmlThird Party Advisory
- https://rustsec.org/advisories/RUSTSEC-2021-0026.htmlThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.