CVE-2026-33176 (GCVE-0-2026-33176)
Vulnerability from cvelistv5 – Published: 2026-03-23 23:29 – Updated: 2026-03-24 18:42
VLAI
EPSS
VEX
Title
Rails Active Support has a possible DoS vulnerability in its number helpers
Summary
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.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-03-24 18:42 UTC
CWE
Assigner
References
7 references
| URL | Tags |
|---|---|
| https://github.com/rails/rails/security/advisorie… | x_refsource_CONFIRM |
| https://github.com/rails/rails/commit/19dbab51ca0… | x_refsource_MISC |
| https://github.com/rails/rails/commit/ebd6be18120… | x_refsource_MISC |
| https://github.com/rails/rails/commit/ee2c59e730e… | x_refsource_MISC |
| https://github.com/rails/rails/releases/tag/v7.2.3.1 | x_refsource_MISC |
| https://github.com/rails/rails/releases/tag/v8.0.4.1 | x_refsource_MISC |
| https://github.com/rails/rails/releases/tag/v8.1.2.1 | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| rails | activesupport |
Affected:
>= 8.1.0.beta1, < 8.1.2.1
Affected: >= 8.0.0.beta1, < 8.0.4.1 Affected: < 7.2.3.1 |
guessed |
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-33176",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-24T18:42:42.653404Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-24T18:42:48.858Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "activesupport",
"vendor": "rails",
"versions": [
{
"status": "affected",
"version": "\u003e= 8.1.0.beta1, \u003c 8.1.2.1"
},
{
"status": "affected",
"version": "\u003e= 8.0.0.beta1, \u003c 8.0.4.1"
},
{
"status": "affected",
"version": "\u003c 7.2.3.1"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "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."
}
],
"metrics": [
{
"cvssV4_0": {
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 6.6,
"baseSeverity": "MEDIUM",
"privilegesRequired": "NONE",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"vectorString": "CVSS: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",
"version": "4.0",
"vulnAvailabilityImpact": "HIGH",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-400",
"description": "CWE-400: Uncontrolled Resource Consumption",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-770",
"description": "CWE-770: Allocation of Resources Without Limits or Throttling",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-23T23:29:27.933Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/rails/rails/security/advisories/GHSA-2j26-frm8-cmj9",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/rails/rails/security/advisories/GHSA-2j26-frm8-cmj9"
},
{
"name": "https://github.com/rails/rails/commit/19dbab51ca086a657bb86458042bc44314916bcb",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/rails/rails/commit/19dbab51ca086a657bb86458042bc44314916bcb"
},
{
"name": "https://github.com/rails/rails/commit/ebd6be18120d1136511eb516338e27af25ac0a1a",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/rails/rails/commit/ebd6be18120d1136511eb516338e27af25ac0a1a"
},
{
"name": "https://github.com/rails/rails/commit/ee2c59e730e5b8faed502cd2c573109df093f856",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/rails/rails/commit/ee2c59e730e5b8faed502cd2c573109df093f856"
},
{
"name": "https://github.com/rails/rails/releases/tag/v7.2.3.1",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/rails/rails/releases/tag/v7.2.3.1"
},
{
"name": "https://github.com/rails/rails/releases/tag/v8.0.4.1",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/rails/rails/releases/tag/v8.0.4.1"
},
{
"name": "https://github.com/rails/rails/releases/tag/v8.1.2.1",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/rails/rails/releases/tag/v8.1.2.1"
}
],
"source": {
"advisory": "GHSA-2j26-frm8-cmj9",
"discovery": "UNKNOWN"
},
"title": "Rails Active Support has a possible DoS vulnerability in its number helpers"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-33176",
"datePublished": "2026-03-23T23:29:27.933Z",
"dateReserved": "2026-03-17T22:16:36.719Z",
"dateUpdated": "2026-03-24T18:42:48.858Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-33176",
"date": "2026-11-01",
"epss": "0.00858",
"percentile": "0.58456"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"product": "activesupport",
"vendor": "rails",
"versions": [
{
"status": "affected",
"version": "\u003e= 8.1.0.beta1, \u003c 8.1.2.1"
},
{
"status": "affected",
"version": "\u003e= 8.0.0.beta1, \u003c 8.0.4.1"
},
{
"status": "affected",
"version": "\u003c 7.2.3.1"
}
]
}
],
"source": "security-advisories@github.com"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:*",
"matchCriteriaId": "D9DC6CB9-DC6C-4CBB-9806-3936ADBC8F1B",
"versionEndExcluding": "7.2.3.1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:*",
"matchCriteriaId": "FA8791E1-8B96-43F6-A3EC-A7E60D700330",
"versionEndExcluding": "8.0.4.1",
"versionStartIncluding": "8.0.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:*",
"matchCriteriaId": "978E0135-D14B-41DE-87E4-CF059A23E189",
"versionEndExcluding": "8.1.2.1",
"versionStartIncluding": "8.1.0",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "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."
},
{
"lang": "es",
"value": "Active Support es un conjunto de herramientas de bibliotecas de soporte y extensiones del n\u00facleo de Ruby extra\u00eddas del framework de Rails. Antes de las versiones 8.1.2.1, 8.0.4.1 y 7.2.3.1, los ayudantes de n\u00fameros de Active Support aceptan cadenas que contienen notaci\u00f3n cient\u00edfica (p. ej. \u00271e10000\u0027), que `BigDecimal` expande en representaciones decimales extremadamente grandes. Esto puede causar una asignaci\u00f3n excesiva de memoria y consumo de CPU cuando el n\u00famero expandido es formateado, posiblemente resultando en una vulnerabilidad de DoS. Las versiones 8.1.2.1, 8.0.4.1 y 7.2.3.1 contienen un parche."
}
],
"id": "CVE-2026-33176",
"lastModified": "2026-06-17T10:37:05.023",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 3.6,
"source": "nvd@nist.gov",
"type": "Primary"
}
],
"cvssMetricV40": [
{
"cvssData": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"availabilityRequirement": "NOT_DEFINED",
"baseScore": 6.6,
"baseSeverity": "MEDIUM",
"confidentialityRequirement": "NOT_DEFINED",
"exploitMaturity": "UNREPORTED",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS: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",
"version": "4.0",
"vulnAvailabilityImpact": "HIGH",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"source": "security-advisories@github.com",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-33176",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-24T18:42:42.653404Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-03-24T00:16:28.807",
"references": [
{
"source": "security-advisories@github.com",
"tags": [
"Patch"
],
"url": "https://github.com/rails/rails/commit/19dbab51ca086a657bb86458042bc44314916bcb"
},
{
"source": "security-advisories@github.com",
"tags": [
"Patch"
],
"url": "https://github.com/rails/rails/commit/ebd6be18120d1136511eb516338e27af25ac0a1a"
},
{
"source": "security-advisories@github.com",
"tags": [
"Patch"
],
"url": "https://github.com/rails/rails/commit/ee2c59e730e5b8faed502cd2c573109df093f856"
},
{
"source": "security-advisories@github.com",
"tags": [
"Release Notes"
],
"url": "https://github.com/rails/rails/releases/tag/v7.2.3.1"
},
{
"source": "security-advisories@github.com",
"tags": [
"Release Notes"
],
"url": "https://github.com/rails/rails/releases/tag/v8.0.4.1"
},
{
"source": "security-advisories@github.com",
"tags": [
"Release Notes"
],
"url": "https://github.com/rails/rails/releases/tag/v8.1.2.1"
},
{
"source": "security-advisories@github.com",
"tags": [
"Vendor Advisory"
],
"url": "https://github.com/rails/rails/security/advisories/GHSA-2j26-frm8-cmj9"
}
],
"sourceIdentifier": "security-advisories@github.com",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-400"
},
{
"lang": "en",
"value": "CWE-770"
}
],
"source": "security-advisories@github.com",
"type": "Secondary"
}
]
}
},
"redhat_vex": {
"aggregate_severity": "Moderate",
"current_release_date": "2026-06-28T07:29:55+00:00",
"cve": "CVE-2026-33176",
"id": "CVE-2026-33176",
"initial_release_date": "2026-03-23T23:29:27.933000+00:00",
"product_status:fixed": "16",
"product_status:known_affected": "1",
"product_status:known_not_affected": "281",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "Rails: Active Support: Active Support: Denial of Service via large scientific notation strings",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33176.json",
"version": "3"
},
"vulnrichment": {
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-33176",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-24T18:42:42.653404Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-24T18:42:45.999Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "activesupport",
"vendor": "rails",
"versions": [
{
"status": "affected",
"version": "\u003e= 8.1.0.beta1, \u003c 8.1.2.1"
},
{
"status": "affected",
"version": "\u003e= 8.0.0.beta1, \u003c 8.0.4.1"
},
{
"status": "affected",
"version": "\u003c 7.2.3.1"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "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."
}
],
"metrics": [
{
"cvssV4_0": {
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 6.6,
"baseSeverity": "MEDIUM",
"privilegesRequired": "NONE",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"vectorString": "CVSS: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",
"version": "4.0",
"vulnAvailabilityImpact": "HIGH",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-400",
"description": "CWE-400: Uncontrolled Resource Consumption",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-770",
"description": "CWE-770: Allocation of Resources Without Limits or Throttling",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-23T23:29:27.933Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/rails/rails/security/advisories/GHSA-2j26-frm8-cmj9",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/rails/rails/security/advisories/GHSA-2j26-frm8-cmj9"
},
{
"name": "https://github.com/rails/rails/commit/19dbab51ca086a657bb86458042bc44314916bcb",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/rails/rails/commit/19dbab51ca086a657bb86458042bc44314916bcb"
},
{
"name": "https://github.com/rails/rails/commit/ebd6be18120d1136511eb516338e27af25ac0a1a",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/rails/rails/commit/ebd6be18120d1136511eb516338e27af25ac0a1a"
},
{
"name": "https://github.com/rails/rails/commit/ee2c59e730e5b8faed502cd2c573109df093f856",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/rails/rails/commit/ee2c59e730e5b8faed502cd2c573109df093f856"
},
{
"name": "https://github.com/rails/rails/releases/tag/v7.2.3.1",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/rails/rails/releases/tag/v7.2.3.1"
},
{
"name": "https://github.com/rails/rails/releases/tag/v8.0.4.1",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/rails/rails/releases/tag/v8.0.4.1"
},
{
"name": "https://github.com/rails/rails/releases/tag/v8.1.2.1",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/rails/rails/releases/tag/v8.1.2.1"
}
],
"source": {
"advisory": "GHSA-2j26-frm8-cmj9",
"discovery": "UNKNOWN"
},
"title": "Rails Active Support has a possible DoS vulnerability in its number helpers"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-33176",
"datePublished": "2026-03-23T23:29:27.933Z",
"dateReserved": "2026-03-17T22:16:36.719Z",
"dateUpdated": "2026-03-24T18:42:48.858Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
Loading timeline…
Loading…
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.