CVE-2026-107288 (GCVE-0-2026-107288)
Vulnerability from cvelistv5 – Published: 2026-10-08 15:18 – Updated: 2026-10-08 17:28
VLAI
EPSS
VEX
Title
Pydantic AI: web_fetch_tool blocked_domains bypass via a hostname the resolver normalizes differently
Summary
Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.77.0 until 1.107.6 and 2.44.0, the local web_fetch_tool and the WebFetch local fallback compare blocked_domains entries with a URL hostname before both values are normalized to the form used by getaddrinfo. An attacker-influenced model can use an equivalent IDNA spelling, non-ASCII label separator, case variation, or trailing root label that resolves to a blocked host but does not match the configured string, causing the application to fetch that host with its own privileges. allowed_domains fails closed for unmatched spellings, and private-IP and cloud-metadata protections remain effective. This issue is fixed in versions 1.107.6 and 2.44.0.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-08 17:28 UTC
CWE
Assigner
References
9 references
| URL | Tags |
|---|---|
| https://github.com/pydantic/pydantic-ai/security/… | x_refsource_CONFIRM |
| https://github.com/pydantic/pydantic-ai/pull/8407 | x_refsource_MISC |
| https://github.com/pydantic/pydantic-ai/pull/8409 | x_refsource_MISC |
| https://github.com/pydantic/pydantic-ai/pull/8421 | x_refsource_MISC |
| https://github.com/pydantic/pydantic-ai/commit/49… | x_refsource_MISC |
| https://github.com/pydantic/pydantic-ai/commit/a9… | x_refsource_MISC |
| https://github.com/pydantic/pydantic-ai/commit/c1… | x_refsource_MISC |
| https://github.com/pydantic/pydantic-ai/releases/… | x_refsource_MISC |
| https://github.com/pydantic/pydantic-ai/releases/… | x_refsource_MISC |
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| pydantic | pydantic-ai |
Affected:
>= 1.77.0, < 1.107.6
Affected: >= 2.0.0b1, < 2.44.0 |
guessed | |
| pydantic | pydantic-ai-slim |
Affected:
>= 1.77.0, < 1.107.6
Affected: >= 2.0.0b1, < 2.44.0 |
guessed |
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-107288",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-10-08T17:28:31.014859Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-10-08T17:28:53.801Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "pydantic-ai",
"vendor": "pydantic",
"versions": [
{
"status": "affected",
"version": "\u003e= 1.77.0, \u003c 1.107.6"
},
{
"status": "affected",
"version": "\u003e= 2.0.0b1, \u003c 2.44.0"
}
]
},
{
"product": "pydantic-ai-slim",
"vendor": "pydantic",
"versions": [
{
"status": "affected",
"version": "\u003e= 1.77.0, \u003c 1.107.6"
},
{
"status": "affected",
"version": "\u003e= 2.0.0b1, \u003c 2.44.0"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.77.0 until 1.107.6 and 2.44.0, the local web_fetch_tool and the WebFetch local fallback compare blocked_domains entries with a URL hostname before both values are normalized to the form used by getaddrinfo. An attacker-influenced model can use an equivalent IDNA spelling, non-ASCII label separator, case variation, or trailing root label that resolves to a blocked host but does not match the configured string, causing the application to fetch that host with its own privileges. allowed_domains fails closed for unmatched spellings, and private-IP and cloud-metadata protections remain effective. This issue is fixed in versions 1.107.6 and 2.44.0."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 3.7,
"baseSeverity": "LOW",
"confidentialityImpact": "LOW",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-918",
"description": "CWE-918: Server-Side Request Forgery (SSRF)",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-1289",
"description": "CWE-1289: Improper Validation of Unsafe Equivalence in Input",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-10-08T15:18:40.047Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-22h6-qm39-v87j",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-22h6-qm39-v87j"
},
{
"name": "https://github.com/pydantic/pydantic-ai/pull/8407",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/pydantic/pydantic-ai/pull/8407"
},
{
"name": "https://github.com/pydantic/pydantic-ai/pull/8409",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/pydantic/pydantic-ai/pull/8409"
},
{
"name": "https://github.com/pydantic/pydantic-ai/pull/8421",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/pydantic/pydantic-ai/pull/8421"
},
{
"name": "https://github.com/pydantic/pydantic-ai/commit/490335f8e2322e143a79337ddca9410e0176c812",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/pydantic/pydantic-ai/commit/490335f8e2322e143a79337ddca9410e0176c812"
},
{
"name": "https://github.com/pydantic/pydantic-ai/commit/a9dab92099d0ef9d5d4aa34ccac8a6f1b0e51284",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/pydantic/pydantic-ai/commit/a9dab92099d0ef9d5d4aa34ccac8a6f1b0e51284"
},
{
"name": "https://github.com/pydantic/pydantic-ai/commit/c1f212a084cbfa0012f2044cdb4731d214b3b983",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/pydantic/pydantic-ai/commit/c1f212a084cbfa0012f2044cdb4731d214b3b983"
},
{
"name": "https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.6",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.6"
},
{
"name": "https://github.com/pydantic/pydantic-ai/releases/tag/v2.44.0",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/pydantic/pydantic-ai/releases/tag/v2.44.0"
}
],
"source": {
"advisory": "GHSA-22h6-qm39-v87j",
"discovery": "UNKNOWN"
},
"title": "Pydantic AI: web_fetch_tool blocked_domains bypass via a hostname the resolver normalizes differently"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-107288",
"datePublished": "2026-10-08T15:18:40.047Z",
"dateReserved": "2026-10-07T15:53:23.586Z",
"dateUpdated": "2026-10-08T17:28:53.801Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-107288",
"date": "2026-11-01",
"epss": "0.00368",
"percentile": "0.30718"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"product": "pydantic-ai",
"vendor": "pydantic",
"versions": [
{
"status": "affected",
"version": "\u003e= 1.77.0, \u003c 1.107.6"
},
{
"status": "affected",
"version": "\u003e= 2.0.0b1, \u003c 2.44.0"
}
]
},
{
"product": "pydantic-ai-slim",
"vendor": "pydantic",
"versions": [
{
"status": "affected",
"version": "\u003e= 1.77.0, \u003c 1.107.6"
},
{
"status": "affected",
"version": "\u003e= 2.0.0b1, \u003c 2.44.0"
}
]
}
],
"source": "security-advisories@github.com"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:a:pydantic:pydantic_ai:*:*:*:*:*:python:*:*",
"matchCriteriaId": "B5355402-6E86-4212-A795-993C09433A3C",
"versionEndExcluding": "1.107.6",
"versionStartIncluding": "1.77.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:pydantic:pydantic_ai:*:-:*:*:*:python:*:*",
"matchCriteriaId": "7FEC7EC8-5520-4930-8853-83108092F8BF",
"versionEndExcluding": "2.44.0",
"versionStartIncluding": "2.0.0",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.77.0 until 1.107.6 and 2.44.0, the local web_fetch_tool and the WebFetch local fallback compare blocked_domains entries with a URL hostname before both values are normalized to the form used by getaddrinfo. An attacker-influenced model can use an equivalent IDNA spelling, non-ASCII label separator, case variation, or trailing root label that resolves to a blocked host but does not match the configured string, causing the application to fetch that host with its own privileges. allowed_domains fails closed for unmatched spellings, and private-IP and cloud-metadata protections remain effective. This issue is fixed in versions 1.107.6 and 2.44.0."
}
],
"id": "CVE-2026-107288",
"lastModified": "2026-10-13T14:35:05.370",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 3.7,
"baseSeverity": "LOW",
"confidentialityImpact": "LOW",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
"version": "3.1"
},
"exploitabilityScore": 2.2,
"impactScore": 1.4,
"source": "security-advisories@github.com",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-107288",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-10-08T17:28:31.014859Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-10-08T16:17:04.147",
"references": [
{
"source": "security-advisories@github.com",
"tags": [
"Patch"
],
"url": "https://github.com/pydantic/pydantic-ai/commit/490335f8e2322e143a79337ddca9410e0176c812"
},
{
"source": "security-advisories@github.com",
"tags": [
"Patch"
],
"url": "https://github.com/pydantic/pydantic-ai/commit/a9dab92099d0ef9d5d4aa34ccac8a6f1b0e51284"
},
{
"source": "security-advisories@github.com",
"tags": [
"Patch"
],
"url": "https://github.com/pydantic/pydantic-ai/commit/c1f212a084cbfa0012f2044cdb4731d214b3b983"
},
{
"source": "security-advisories@github.com",
"tags": [
"Patch",
"Vendor Advisory"
],
"url": "https://github.com/pydantic/pydantic-ai/pull/8407"
},
{
"source": "security-advisories@github.com",
"tags": [
"Patch",
"Vendor Advisory"
],
"url": "https://github.com/pydantic/pydantic-ai/pull/8409"
},
{
"source": "security-advisories@github.com",
"tags": [
"Patch",
"Vendor Advisory"
],
"url": "https://github.com/pydantic/pydantic-ai/pull/8421"
},
{
"source": "security-advisories@github.com",
"tags": [
"Patch",
"Release Notes",
"Vendor Advisory"
],
"url": "https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.6"
},
{
"source": "security-advisories@github.com",
"tags": [
"Patch",
"Release Notes",
"Vendor Advisory"
],
"url": "https://github.com/pydantic/pydantic-ai/releases/tag/v2.44.0"
},
{
"source": "security-advisories@github.com",
"tags": [
"Mitigation",
"Vendor Advisory"
],
"url": "https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-22h6-qm39-v87j"
}
],
"sourceIdentifier": "security-advisories@github.com",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-918"
},
{
"lang": "en",
"value": "CWE-1289"
}
],
"source": "security-advisories@github.com",
"type": "Secondary"
}
]
}
},
"redhat_vex": {
"aggregate_severity": "Low",
"current_release_date": "2026-10-15T23:47:05+00:00",
"cve": "CVE-2026-107288",
"id": "CVE-2026-107288",
"initial_release_date": "2026-10-08T15:18:40.047000+00:00",
"product_status:known_affected": "5",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "pydantic-ai: pydantic-ai: Domain blocklist bypass via unnormalized hostname comparison",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-107288.json",
"version": "3"
},
"vulnrichment": {
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-107288",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-10-08T17:28:31.014859Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-10-08T17:28:33.935Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "pydantic-ai",
"vendor": "pydantic",
"versions": [
{
"status": "affected",
"version": "\u003e= 1.77.0, \u003c 1.107.6"
},
{
"status": "affected",
"version": "\u003e= 2.0.0b1, \u003c 2.44.0"
}
]
},
{
"product": "pydantic-ai-slim",
"vendor": "pydantic",
"versions": [
{
"status": "affected",
"version": "\u003e= 1.77.0, \u003c 1.107.6"
},
{
"status": "affected",
"version": "\u003e= 2.0.0b1, \u003c 2.44.0"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.77.0 until 1.107.6 and 2.44.0, the local web_fetch_tool and the WebFetch local fallback compare blocked_domains entries with a URL hostname before both values are normalized to the form used by getaddrinfo. An attacker-influenced model can use an equivalent IDNA spelling, non-ASCII label separator, case variation, or trailing root label that resolves to a blocked host but does not match the configured string, causing the application to fetch that host with its own privileges. allowed_domains fails closed for unmatched spellings, and private-IP and cloud-metadata protections remain effective. This issue is fixed in versions 1.107.6 and 2.44.0."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 3.7,
"baseSeverity": "LOW",
"confidentialityImpact": "LOW",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-918",
"description": "CWE-918: Server-Side Request Forgery (SSRF)",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-1289",
"description": "CWE-1289: Improper Validation of Unsafe Equivalence in Input",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-10-08T15:18:40.047Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-22h6-qm39-v87j",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-22h6-qm39-v87j"
},
{
"name": "https://github.com/pydantic/pydantic-ai/pull/8407",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/pydantic/pydantic-ai/pull/8407"
},
{
"name": "https://github.com/pydantic/pydantic-ai/pull/8409",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/pydantic/pydantic-ai/pull/8409"
},
{
"name": "https://github.com/pydantic/pydantic-ai/pull/8421",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/pydantic/pydantic-ai/pull/8421"
},
{
"name": "https://github.com/pydantic/pydantic-ai/commit/490335f8e2322e143a79337ddca9410e0176c812",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/pydantic/pydantic-ai/commit/490335f8e2322e143a79337ddca9410e0176c812"
},
{
"name": "https://github.com/pydantic/pydantic-ai/commit/a9dab92099d0ef9d5d4aa34ccac8a6f1b0e51284",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/pydantic/pydantic-ai/commit/a9dab92099d0ef9d5d4aa34ccac8a6f1b0e51284"
},
{
"name": "https://github.com/pydantic/pydantic-ai/commit/c1f212a084cbfa0012f2044cdb4731d214b3b983",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/pydantic/pydantic-ai/commit/c1f212a084cbfa0012f2044cdb4731d214b3b983"
},
{
"name": "https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.6",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.6"
},
{
"name": "https://github.com/pydantic/pydantic-ai/releases/tag/v2.44.0",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/pydantic/pydantic-ai/releases/tag/v2.44.0"
}
],
"source": {
"advisory": "GHSA-22h6-qm39-v87j",
"discovery": "UNKNOWN"
},
"title": "Pydantic AI: web_fetch_tool blocked_domains bypass via a hostname the resolver normalizes differently"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-107288",
"datePublished": "2026-10-08T15:18:40.047Z",
"dateReserved": "2026-10-07T15:53:23.586Z",
"dateUpdated": "2026-10-08T17:28:53.801Z",
"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.