CVE-2026-61845
Crass: Large numeric exponents cause CPU and memory denial of service
CVE-2026-61845 is a high vulnerability (CVSS 8.9) in Rgrove Crass, published October 20, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.39%, the 32nd percentile. Fixed in crass 1.0.7.
Crass is a Ruby CSS parser that's fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, Crass converts CSS scientific notation number values with unbounded exponentiation before clamping 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, potentially resulting in a crash. This issue is fixed in version 1.0.7.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
8.9
Crass: Large numeric exponents cause CPU and memory denial of service
Crass is a Ruby CSS parser that's fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, Crass converts CSS scientific notation number values with unbounded exponentiation before clamping 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, potentially resulting in a crash. This issue is fixed in version 1.0.7.
- Record
CVE-2026-61845- CVSS 4.0
- 8.9 High
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 - Weakness
- CWE-789
- Updated
- 2026-11-02
EUVDEUVD-2026-114321
8.9
Crass is a Ruby CSS parser that's fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, Crass converts CSS scientific notation number values with unbounded exponentiation before clamping 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, potentially resulting in a crash. This issue is fixed in version 1.0.7.
- Record
EUVD-2026-114321- CVSS 4.0
- 8.9 High
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-6wmf-3r64-vcwv
8.9
Crass : Large numeric exponents cause CPU and memory denial of service
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
- Record
GHSA-6wmf-3r64-vcwv- CVSS 4.0
- 8.9 High
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 - Weakness
- CWE-674
- Updated
- 2026-11-02
NVD
8.9
Crass is a Ruby CSS parser that's fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, Crass converts CSS scientific notation number values with unbounded exponentiation before clamping 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, potentially resulting in a crash. This issue is fixed in version 1.0.7.
- Record
CVE-2026-61845- CVSS 4.0
- 8.9 High
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/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 - Weakness
- CWE-789
- Updated
- 2026-11-02
OSV
8.9
Crass: Large numeric exponents cause CPU and memory denial of service
Crass is a Ruby CSS parser that's fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, Crass converts CSS scientific notation number values with unbounded exponentiation before clamping 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, potentially resulting in a crash. This issue is fixed in version 1.0.7.
- Record
CVE-2026-61845- CVSS 4.0
- 8.9 High
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 - Weakness
- CWE-789
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-61845
8.9
Crass is a Ruby CSS parser that's fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, Crass converts CSS scientific notation number values with unbounded exponentiation before clamping 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, potentially resulting in a crash. This issue is fixed in version 1.0.7.
- Record
DEBIAN-CVE-2026-61845- CVSS 4.0
- 8.9 High
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/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 - Updated
- 2026-11-02
OSVGHSA-6wmf-3r64-vcwv
8.9
Crass : Large numeric exponents cause CPU and memory denial of service
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
- Record
GHSA-6wmf-3r64-vcwv- CVSS 4.0
- 8.9 High
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 - Weakness
- CWE-674
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-61845
8.9
Crass is a Ruby CSS parser that's fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, Crass converts CSS scientific notation number values with unbounded exponentiation before clamping 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, potentially resulting in a crash. This issue is fixed in version 1.0.7.
- Record
UBUNTU-CVE-2026-61845- CVSS 4.0
- 8.9 High
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 - Updated
- 2026-11-04
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
crassRubyGems |
before 1.0.7 | 1.0.7 |
ruby-crassDebian:12 |
All versions, plus listed versions 1.0.2-31.0.6-11.0.7-11.0.8-1 |
None known |
ruby-crassDebian:13 |
All versions, plus listed versions 1.0.6-11.0.7-11.0.8-1 |
None known |
ruby-crassDebian:14 |
before 1.0.7-1, plus listed versions 1.0.6-1 |
1.0.7-1 |
crassRubyGems |
before 1.0.7, plus listed versions 0.0.10.0.20.1.00.2.00.2.1 Show 7 moreShow less1.0.01.0.11.0.21.0.31.0.41.0.51.0.6 |
1.0.7 |
ruby-crassUbuntu:16.04:LTS |
All versions, plus listed versions 1.0.2-2 |
None known |
ruby-crassUbuntu:18.04:LTS |
All versions, plus listed versions 1.0.2-2 |
None known |
ruby-crassUbuntu:20.04:LTS |
All versions, plus listed versions 1.0.2-2 |
None known |
ruby-crassUbuntu:22.04:LTS |
All versions, plus listed versions 1.0.2-2.11.0.2-3 |
None known |
ruby-crassUbuntu:24.04:LTS |
All versions, plus listed versions 1.0.2-3 |
None known |
ruby-crassUbuntu:26.10 |
All versions, plus listed versions 1.0.6-1ubuntu1 |
None known |
ruby-crassUbuntu:26.04:LTS |
All versions, plus listed versions 1.0.6-1ubuntu1 |
None known |
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-04 | affected, aliases, facts, references | OSV |
| 2026-11-02 | created | CVE List, EUVD, GitHub Advisories, NVD, OSV |
References
github.com/rgrove/crass/security/advisories/GHSA-6wmf-3r64-vcwv
github.com/rgrove/crass/commit/ea6726b7f7cf7e85b23aa2240b8512b4f8d11ad9
github.com/rgrove/crass/releases/tag/v1.0.7
github.com/rubysec/ruby-advisory-db/blob/master/gems/crass/GHSA-6wmf-3r64-vcwv.yml
rubygems.org/gems/crass/versions/1.0.7
github.com/advisories/GHSA-6wmf-3r64-vcwv