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GHSA-6wmf-3r64-vcwv CVE-2026-61845

Crass : Large numeric exponents cause CPU and memory denial of service

High RubyGems
Severity
0.0 / 10
High · CVSS 4.0
Exploit chance (EPSS)
0.39%
Chance of exploitation in the next 30 days. Higher than 32.73% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-674 Uncontrolled Recursion
Fix
1.0.7
Upgrade crass to this version or later

Description

Impact

Crass converts CSS scientific notation number values with unbounded exponentiation before it clamps the result to Float::MAX. Applications that use Crass to parse attacker-controlled CSS strings can be forced to spend disproportionate CPU and memory parsing a tiny input, possibly resulting in a crash.

Patches

This is fixed in Crass 1.0.7.

Related

Affected versions

RubyGems

PackageVulnerableFixed in
crass
< 1.0.7
1.0.7

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

crass RubyGems → 1.0.7

bundler
bundle update crass # Gemfile: gem "crass", ">= 1.0.7"

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H

Attack vector
Network
Attack complexity
Low
Attack requirements
Present
Privileges required
None
User interaction
None
Confidentiality (vulnerable system)
None
Integrity (vulnerable system)
None
Availability (vulnerable system)
High
Confidentiality (subsequent systems)
None
Integrity (subsequent systems)
None
Availability (subsequent systems)
High

Weakness

CWE-674: Uncontrolled Recursion

The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.

How to prevent it
  • Implementation: Ensure that an end condition will be reached under all logic conditions. The end condition may include checking against the depth of recursion and exiting with an error if the recursion goes too deep. The complexity of the end condition contributes to the effectiveness of this action.
  • Implementation: Increase the stack size.

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-8vfg-2r28-hvhj
Crass: Non-ASCII characters cause superlinear CPU consumption
Medium Also affects crass
GHSA-wwpr-jff3-395c
Crass: A large number of adjacent CSS comments can trigger a SystemStackError
Medium Also affects crass
GHSA-6jxj-px6v-747w
Crass: Deeply nested CSS blocks and functions can trigger a SystemStackError or excessive memory usage
Medium Also affects crass
GHSA-pq4g-8rxf-4g29
Crass: Incorrect tokenization of bad URLs enables CSS sanitizer bypass
Medium Also affects crass
GHSA-hqq3-7jhf-c5jx
Forge: Denial of service in TLS record processing via call stack exhaustion
High Same weakness, CWE-674
GHSA-vvm8-gf78-28g4
Go JOSE: Panics in JSON parsing
Medium Same weakness, CWE-674
EEF-CVE-2026-65628
Infinite recursion (CPU denial-of-service) in JOSE.JWK.shared_secret/2 on mismatched key types
Not rated yet Same weakness, CWE-674
GHSA-c9rx-x947-fp3h
ApostropheCMS sanitize-html: unbounded recursion when re-sanitizing the fallback of a discarded iframe (stack overflow, nestingLimit not enforced)
Medium Same weakness, CWE-674
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