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Fencer Vulns
medium 6.3

CVE-2026-61846 json

Crass: Deeply nested CSS blocks and functions can trigger a SystemStackError or excessive memory usage

published 2026-10-29 10 d ago modified 2026-11-05 4 d ago also GHSA-6jxj-px6v-747w , EUVD-2026-114322

cvss
6.3
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 42%
public exploits
0
none known

Summary

Crass is a Ruby CSS parser that's fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, Crass recursively parses `CSS simple blocks and functions` without a depth guard. An attacker-controlled CSS value containing deeply nested blocks or functions can recurse until Ruby raises `SystemStackError`: stack level too deep, or cause excessive memory usage. Version 1.0.7 adds a configurable depth limit with a conservative default. This issue is fixed in version 1.0.7.

Patch / fix

  • rubygems crass 1.0.7
  • ruby-crass Debian 14 1.0.7-1

debian advisories DEBIAN-CVE-2026-61846

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-61846 updated cvss 5.3

crass: crass: Denial of Service via deeply nested CSS structures

  • Red Hat 3scale API Management Platform 2 3scale-amp2/zync-rhel9, 3scale-amp2/system-rhel8, 3scale-amp2/system-rhel9
    affected: no fix available, no fix planned “Out of support scope”
  • Red Hat Satellite 6 rubygem-crass 1.0.6-2.el9sat
    affected: no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
4 d ago

Exploit prediction

0.49% chance of exploitation in the next 30 days, higher than 42% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 6.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L
CNA 4.0 6.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L/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:X

Affected packages

ecosystem package affected fixed in
rubygems crass
<1.0.7
1.0.7

Affected products

  • rgrove crass

Classification

Weakness
  • CWE-674 Uncontrolled Recursion
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.