GHSA-HX8V-G79F-8W5F
Vulnerability from github – Published: 2026-09-17 14:51 – Updated: 2026-09-17 14:51Summary
A server-side request forgery in LiteLLM Proxy lets an authenticated caller redirect the
proxy's outbound request to a host of their choosing by smuggling an api_base inside the
user_config request body, bypassing the existing parameter guard.
Details
LiteLLM Proxy validates request bodies with is_request_body_safe, which blocks the
api_base and base_url parameters but does not cover user_config. The user_config
object is used to build the outbound router for a request, so a caller can place an
api_base inside it and reach an arbitrary host. The guard only inspected the two
top-level keys, so the same api_base nested inside user_config was never checked.
Exploitation requires a valid virtual key.
Impact
An authenticated caller can make the proxy issue server-side requests to internal or external hosts of their choosing, reaching endpoints the caller cannot otherwise access.
Affected / Patched
Affected: <= 1.83.8
Patched: 1.83.9
Remediation
Upgrade to 1.83.9 or later (released 2026-04-17).
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 1.83.8"
},
"package": {
"ecosystem": "PyPI",
"name": "litellm"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.83.9"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-59823"
],
"database_specific": {
"cwe_ids": [
"CWE-918"
],
"github_reviewed": true,
"github_reviewed_at": "2026-09-17T14:51:21Z",
"nvd_published_at": "2026-09-16T19:17:21Z",
"severity": "MODERATE"
},
"details": "### Summary\nA server-side request forgery in LiteLLM Proxy lets an authenticated caller redirect the\nproxy\u0027s outbound request to a host of their choosing by smuggling an `api_base` inside the\n`user_config` request body, bypassing the existing parameter guard.\n\n### Details\nLiteLLM Proxy validates request bodies with `is_request_body_safe`, which blocks the\n`api_base` and `base_url` parameters but does not cover `user_config`. The `user_config`\nobject is used to build the outbound router for a request, so a caller can place an\n`api_base` inside it and reach an arbitrary host. The guard only inspected the two\ntop-level keys, so the same `api_base` nested inside `user_config` was never checked.\n\nExploitation requires a valid virtual key.\n\n### Impact\nAn authenticated caller can make the proxy issue server-side requests to internal or\nexternal hosts of their choosing, reaching endpoints the caller cannot otherwise access.\n\n### Affected / Patched\nAffected: `\u003c= 1.83.8`\nPatched: `1.83.9`\n\n### Remediation\nUpgrade to 1.83.9 or later (released 2026-04-17).",
"id": "GHSA-hx8v-g79f-8w5f",
"modified": "2026-09-17T14:51:21Z",
"published": "2026-09-17T14:51:21Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/BerriAI/litellm/security/advisories/GHSA-hx8v-g79f-8w5f"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59823"
},
{
"type": "WEB",
"url": "https://github.com/BerriAI/litellm/pull/25827"
},
{
"type": "WEB",
"url": "https://github.com/BerriAI/litellm/commit/47214be317f45a2d2ac08258362e0481411eb427"
},
{
"type": "PACKAGE",
"url": "https://github.com/BerriAI/litellm"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "LiteLLM Proxy has server-side request forgery via the `user_config` request parameter"
}
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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