CVE-2026-55149 (GCVE-0-2026-55149)
Vulnerability from cvelistv5 – Published: 2026-09-15 16:30 – Updated: 2026-09-15 16:30
VLAI
EPSS
VEX
Title
Vouch Proxy: Unbounded Multipart Cookie Allocation DoS
Summary
Vouch Proxy is an SSO and OAuth/OIDC login solution for Nginx using the auth_request module. Prior to 0.48.0, Cookie in pkg/cookie/cookie.go parses the total part count from an attacker-controlled multipart cookie name and passes the value to make([]string, numParts) without checking that the value is positive or reasonably bounded. Requests to /validate and /_external-auth-:id reach JWTCacheHandler in pkg/jwtmanager/jwtcache.go, FindJWT in pkg/jwtmanager/jwtmanager.go, and the vulnerable cookie reassembly before JWT validation, so no account or valid session is required. A cookie name such as VouchCookie_1of10000000000 causes an attempted slice allocation of roughly 160 GB and a fatal Go runtime out-of-memory condition, allowing one request to crash the authentication proxy and repeated requests to sustain unavailability. This vulnerability is fixed in 0.48.0.
Severity
7.5 (High)
CWE
- CWE-789 - Memory Allocation with Excessive Size Value
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/vouch/vouch-proxy/security/adv… | x_refsource_CONFIRM |
| https://github.com/vouch/vouch-proxy/commit/fa18c… | x_refsource_MISC |
| https://github.com/vouch/vouch-proxy/releases/tag… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| vouch | vouch-proxy |
Affected:
< 0.48.0
|
guessed |
{
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"product": "vouch-proxy",
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"versions": [
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"descriptions": [
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}
],
"metrics": [
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"attackVector": "NETWORK",
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"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"
}
}
],
"problemTypes": [
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"descriptions": [
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"cweId": "CWE-789",
"description": "CWE-789: Memory Allocation with Excessive Size Value",
"lang": "en",
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"providerMetadata": {
"dateUpdated": "2026-09-15T16:30:37.580Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
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"references": [
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"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/vouch/vouch-proxy/security/advisories/GHSA-qqff-5854-px68"
},
{
"name": "https://github.com/vouch/vouch-proxy/commit/fa18ce30ba50a4863a436acad044c22965329c4f",
"tags": [
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],
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},
{
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"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/vouch/vouch-proxy/releases/tag/v0.48.0"
}
],
"source": {
"advisory": "GHSA-qqff-5854-px68",
"discovery": "UNKNOWN"
},
"title": "Vouch Proxy: Unbounded Multipart Cookie Allocation DoS"
}
},
"cveMetadata": {
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"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-55149",
"datePublished": "2026-09-15T16:30:37.580Z",
"dateReserved": "2026-06-16T15:13:28.164Z",
"dateUpdated": "2026-09-15T16:30:37.580Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"nvd": "{\"cve\":{\"id\":\"CVE-2026-55149\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-09-15T17:17:21.893\",\"lastModified\":\"2026-09-15T17:17:21.893\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Vouch Proxy is an SSO and OAuth/OIDC login solution for Nginx using the auth_request module. Prior to 0.48.0, Cookie in pkg/cookie/cookie.go parses the total part count from an attacker-controlled multipart cookie name and passes the value to make([]string, numParts) without checking that the value is positive or reasonably bounded. Requests to /validate and /_external-auth-:id reach JWTCacheHandler in pkg/jwtmanager/jwtcache.go, FindJWT in pkg/jwtmanager/jwtmanager.go, and the vulnerable cookie reassembly before JWT validation, so no account or valid session is required. A cookie name such as VouchCookie_1of10000000000 causes an attempted slice allocation of roughly 160 GB and a fatal Go runtime out-of-memory condition, allowing one request to crash the authentication proxy and repeated requests to sustain unavailability. This vulnerability is fixed in 0.48.0.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"vouch\",\"product\":\"vouch-proxy\",\"versions\":[{\"version\":\"\u003c 0.48.0\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-789\"}]}],\"references\":[{\"url\":\"https://github.com/vouch/vouch-proxy/commit/fa18ce30ba50a4863a436acad044c22965329c4f\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/vouch/vouch-proxy/releases/tag/v0.48.0\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/vouch/vouch-proxy/security/advisories/GHSA-qqff-5854-px68\",\"source\":\"security-advisories@github.com\"}]}}",
"suse_vex": {
"aggregate_severity": "important",
"current_release_date": "2026-09-16T00:09:59Z",
"cve": "CVE-2026-55149",
"id": "CVE-2026-55149",
"initial_release_date": "2026-09-05T00:31:22Z",
"source": "SUSE CSAF VEX",
"status": "interim",
"title": "SUSE CVE CVE-2026-55149",
"url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-55149.json",
"version": "3"
}
}
}
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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.
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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.
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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.
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