6.3
MediumCVSS 4.0 · from GitHub_M
CVE-2026-61847
Crass: A large number of adjacent CSS comments can trigger a SystemStackError
crass · CWE-674 · CWE-674Affectedcrass
FixNo fix listed yet.
PublishedOct 30, 18:44 · GitHub_M
ScoredOct 30 · 6.3 · GitHub_M
Exploit code publicNone known · checked 21:18 UTC
ExploitedNone known · CISA KEV checked 22:06 UTC
What we know
No known exploitation. CISA KEV, checked 22:06 UTC.
No public exploit code known. Exploit-DB, Metasploit, Nuclei, checked 21:18 UTC.
An attacker only needs network access to the target. No login needed. CVSS: network, no privileges.
It only works under certain conditions, which makes it harder to pull off. CVSS: high attack complexity.
Description
Crass is a Ruby CSS parser that's fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, when the `:preserve_comments` option is not enabled, which is the default, Crass discards CSS comments by recursively consuming the next token. An attacker-provided stylesheet containing a very large number of adjacent comments can cause excessive recursion and trigger a `SystemStackError`, denying service to the parsing application. Preserving comments avoids this recursive path. This issue is fixed in version 1.0.7.
From GitHub_M
Affected and fixed versions
ProductAffectedFixed incrass< 1.0.7–
Exploit code
Exploit-DBnone knownMetasploitnone knownNucleinone known