CVE-2026-18353: Unauthenticated SSRF in PIA via OIDC issuer allowlist bypass

Severity: high (CVSS 8.8 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-30 · updated 2026-10-23
Weakness: CWE-918

Description

PIA's `POST /v1/upload/sbom` endpoint accepts a Bearer JWT and checks its **unverified** `iss` claim against an issuer allowlist using Python's `urlparse` before performing OIDC discovery with `requests`. Because `urlparse` and `requests`/`urllib3` parse an authority string containing a backslash (e.g. `https://attacker-host\@ci.eclipse.org/`) into *different* hostnames, an attacker can craft an issuer that passes the allowlist check yet drives `requests` — and subsequently `urllib.request.urlopen` for JWKS retrieval — to connect to an arbitrary attacker-chosen host, port, and scheme.

Affected products

Eclipse Foundation Eclipse CSI - PIA: from 0.4.0 before 0.6.0 — fixed in 0.6.0

How to fix

Upgrade to a fixed version: Eclipse Foundation Eclipse CSI - PIA 0.6.0. Check the vendor advisory for mitigations.

References

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