CVE-2026-18353
Received Received - Intake

Bearer JWT Issuer Spoofing in PIA SBOM Upload

Publication date: 2026-07-30

Last updated on: 2026-07-30

Assigner: Eclipse Foundation

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.

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Meta Information

Published
2026-07-30
Last Modified
2026-07-30
Generated
2026-07-30
AI Q&A
2026-07-30
EPSS Evaluated
N/A
NVD
CVE-2026-18353
EUVD
EUVD-2026-51066

Affected Vendors & Products

Showing 4 associated CPEs
Vendor Product Version / Range
python urlparse *
python requests *
python urllib3 *
eclipse pia From 0.4.0 (inc) to 0.5.0 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-918 The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

Attack-Flow Graph

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Executive Summary

CVE-2026-18353 is a Server-Side Request Forgery (SSRF) vulnerability in PIA's software affecting versions 0.4.0 to 0.5.0. It occurs in the POST /v1/upload/sbom endpoint where the OIDC issuer allowlist is improperly validated. An attacker crafts a malicious issuer URL with a backslash that is parsed differently by Python's urlparse and the requests library, allowing the attacker to bypass the allowlist and force the server to make outbound requests to arbitrary hosts, ports, and schemes.

Detection Guidance

To detect this vulnerability, inspect network logs for outbound requests from the PIA server to unexpected hosts or ports. Check for URLs containing backslashes in issuer claims. Monitor for SSRF indicators like connections to internal IP ranges or cloud metadata endpoints.

Impact Analysis

This vulnerability enables blind SSRF, meaning attackers cannot see responses but can probe internal hosts, exfiltrate data, or interact with internal services like cloud metadata endpoints. It allows unauthorized outbound connections without authentication, potentially leading to data breaches or further network compromise.

Compliance Impact

This vulnerability could lead to unauthorized data access or exfiltration, violating GDPR's data protection requirements and HIPAA's safeguards for protected health information. Non-compliance may result in legal penalties, fines, or reputational damage.

Mitigation Strategies

Immediately disable the affected POST /v1/upload/sbom endpoint if possible. Update to a patched version once available. If no patch exists, implement strict issuer validation by reconstructing the issuer from validated components and ensuring consistent URL parsing between allowlist checks and request execution.

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