CVE-2026-33176: Rails Active Support has a possible DoS vulnerability in its number helpers
Vulnerability summary
CVE-2026-33176 is a high (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in rails activesupport. EPSS estimates a 0.86% chance of exploitation in the next 30 days, higher than 58.4% of scored vulnerabilities.
Not severe (CVSS 6.6, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 3 · Related 1Timeline
- 23-03-2026PublishedVulnerability first disclosed.
- 24-03-2026Last modifiedVulnerability information updated.
Description
Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, Active Support number helpers accept strings containing scientific notation (e.g. `1e10000`), which `BigDecimal` expands into extremely large decimal representations. This can cause excessive memory allocation and CPU consumption when the expanded number is formatted, possibly resulting in a DoS vulnerability. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.
CVSS metrics
9 scores · 7 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:UDiffers
- OSV · WolfiEcosystem advisory · calculated8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:UDiffers
- OSV · ChainguardEcosystem advisory · calculated8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:UDiffers
- OSV · RubygemsEcosystem advisory · calculated8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:UDiffers
- NVDNIST6.6MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/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
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.86%
Chance of exploitation in the next 30 days
Percentile
58%
Versus all other CVEs
30-day change
Decrease -0.11 pp
From 0.97% on 04-10-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-400Uncontrolled Resource ConsumptionThe product does not properly control the allocation and maintenance of a limited resource.
- CWE-770Allocation of Resources Without Limits or ThrottlingThe product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
Affected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Chainguard29 products
- cinc-auditor< 7.0.107-r1
- gitlab-rails-ce-18.1All versions (No fix recorded)
- gitlab-rails-ce-18.10< 18.10.3-r1
- gitlab-rails-ce-18.2All versions (No fix recorded)
- gitlab-rails-ce-18.3All versions (No fix recorded)
Wolfi4 products
- cinc-auditor< 7.0.107-r1
- kube-fluentd-operator< 1.18.2-r60
- kube-logging-operator-fluentd-outputs< 6.4.0-r9
- ruby3.2-rails-8.1< 8.1.3-r0
Debian1 product
- rails< 2:6.1.7.10+dfsg-1~deb12u3 | < 2:7.2.2.2+dfsg-2~deb13u2 | < 2:7.2.3.1+dfsg-1
Rails1 product
- activesupport≥ 8.1.0.beta1, < 8.1.2.1 | ≥ 8.0.0.beta1, < 8.0.4.1 | < 7.2.3.1
RubyGems1 product
- activesupport≥ 8.1.0.beta1, < 8.1.2.1 | ≥ 8.0.0.beta1, < 8.0.4.1 | < 7.2.3.1
Rubyonrails1 product
- rails< 7.2.3.1 | ≥ 8.0.0, < 8.0.4.1 | ≥ 8.1.0, < 8.1.2.1
Ubuntu1 product
- railsAll versions (No fix recorded)
7 vendors · 38 products
References
14 links- github.com/rails/rails/security/advisories/GHSA-2j26-frm8-cmj9X Refsource CONFIRMREPORTAdvisoryWEBVendor Advisory
- github.com/rails/rails/commit/19dbab51ca086a657bb86458042bc44314916bcbX Refsource MISCREPORTFIXWEBPatch
- github.com/rails/rails/commit/ebd6be18120d1136511eb516338e27af25ac0a1aX Refsource MISCREPORTFIXWEBPatch
- github.com/rails/rails/commit/ee2c59e730e5b8faed502cd2c573109df093f856X Refsource MISCREPORTFIXWEBPatch