GCVE-1-2026-20093 (CVE-2026-86452)
Vulnerability from gna-1 – Published: 2026-09-07 13:03 – Updated: 2026-09-07 13:03
VLAI
EPSS
VEX
Title
MISP Unauthenticated Mail Endpoints Allow Unbounded Storage Consumption and Request Flooding
Summary
Affected versions of MISP permit unauthenticated or weakly constrained request paths to perform persistent work without adequate input bounds or rate limiting.
The users/forgot password-reset endpoint accepted an attacker-controlled email value without first imposing a reasonable length bound or validating its format. That value was then used to create an audit log entry and queue a password-reset job, causing the supplied value to be persisted more than once per request. The commit explicitly states that an unbounded unauthenticated request field was stored twice per call with no throttle.
The fix adds:
*
a maximum email input length of 1024 bytes;
*
email-format validation before persistent work;
*
a per-source pre-authentication request budget;
*
HTTP 429 responses when that budget is exceeded;
*
a 15-minute cooldown for API-access request emails;
*
POST-only handling and CSRF protection for the API-access request endpoint.
The new flood filter is specifically intended to limit persistent storage costs from anonymous requests such as password resets, registrations, and failed REST authentication attempts.
Version affected: ≤2.5.45
Severity
CWE
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://github.com/MISP/MISP/commit/d75d899be | patch |
Impacted products
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"containers": {
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"repo": "https://github.com/MISP/MISP",
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"status": "affected",
"version": "0",
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"credits": [
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"lang": "en",
"type": "finder",
"value": "Scottish Government - National Cyber Team"
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{
"lang": "en",
"type": "remediation developer",
"value": "iglocska"
},
{
"lang": "en",
"type": "remediation developer",
"value": "Claude Opus 5 (1M context)"
}
],
"descriptions": [
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"value": "\u003cp\u003eAffected versions of MISP permit unauthenticated or weakly constrained request paths to perform persistent work without adequate input bounds or rate limiting.\u003c/p\u003e\n\u003cp\u003eThe \u003ccode\u003eusers/forgot\u003c/code\u003e password-reset endpoint accepted an attacker-controlled email value without first imposing a reasonable length bound or validating its format. That value was then used to create an audit log entry and queue a password-reset job, causing the supplied value to be persisted more than once per request. The commit explicitly states that an \u003cstrong\u003eunbounded unauthenticated request field was stored twice per call with no throttle\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003eThe fix adds:\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003e\na maximum email input length of 1024 bytes;\n\u003c/li\u003e\n\u003cli\u003e\nemail-format validation before persistent work;\n\u003c/li\u003e\n\u003cli\u003e\na per-source pre-authentication request budget;\n\u003c/li\u003e\n\u003cli\u003e\nHTTP 429 responses when that budget is exceeded;\n\u003c/li\u003e\n\u003cli\u003e\na 15-minute cooldown for API-access request emails;\n\u003c/li\u003e\n\u003cli\u003e\nPOST-only handling and CSRF protection for the API-access request endpoint.\n\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eThe new flood filter is specifically intended to limit persistent storage costs from anonymous requests such as password resets, registrations, and failed REST authentication attempts.\u003c/p\u003eVersion affected: \u22642.5.45\u003cbr\u003e"
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"value": "Affected versions of MISP permit unauthenticated or weakly constrained request paths to perform persistent work without adequate input bounds or rate limiting.\n\n\nThe users/forgot password-reset endpoint accepted an attacker-controlled email value without first imposing a reasonable length bound or validating its format. That value was then used to create an audit log entry and queue a password-reset job, causing the supplied value to be persisted more than once per request. The commit explicitly states that an unbounded unauthenticated request field was stored twice per call with no throttle.\n\n\nThe fix adds:\n\n\n\n * \na maximum email input length of 1024 bytes;\n\n\n * \nemail-format validation before persistent work;\n\n\n * \na per-source pre-authentication request budget;\n\n\n * \nHTTP 429 responses when that budget is exceeded;\n\n\n * \na 15-minute cooldown for API-access request emails;\n\n\n * \nPOST-only handling and CSRF protection for the API-access request endpoint.\n\n\n\n\n\nThe new flood filter is specifically intended to limit persistent storage costs from anonymous requests such as password resets, registrations, and failed REST authentication attempts.\n\nVersion affected: \u22642.5.45"
}
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"baseScore": 8.7,
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"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
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"url": "https://github.com/MISP/MISP/commit/d75d899be"
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"title": "MISP Unauthenticated Mail Endpoints Allow Unbounded Storage Consumption and Request Flooding",
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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.
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.
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