CVE-2026-75628: Punk::OAuth2 versions before 0.03 for Perl allow an at
CVE-2026-75628 analysis covering impact, affected products, versions, remediation, and cross-checked defender guidance.
CVE-2026-75628 is a vulnerability published by NVD on 8/20/2026.
What happened
Punk::OAuth2 versions before 0.03 for Perl allow an attacker-chosen off-site redirect after login because same_origin_path accepts a backslash or tab in the return parameter.
oauth2_login reads the return parameter from the initiation request, runs same_origin_path over it, and stores the survivor in the session flow record as the post-login redirect target. That check rejects a value that does not begin with a slash, one with a slash as its second byte, and one containing CR or LF. A backslash and a tab pass. The URL Standard treats a backslash as equivalent to a slash for special schemes, so `/\evil.example` parses with the authority `evil.example`. It also strips ASCII tab before parsing, so a tab between two leading slashes leaves `//evil.example`.
A crafted link to the application's own login route lands the victim on the attacker's site after a genuine authentication. The redirect carries no authorization code or access token.
Affected products and versions
- NVD has not published a normalized affected-product configuration yet.
Severity and weakness
CVSS: N/A . Vector: not available.
Weaknesses: CWE-601.
Known exploitation
No CISA KEV entry is currently attached to the NVD record.
What defenders should do
- Identify whether the affected product and version range exists in production.
- Review vendor advisories and release notes before change windows.
- Patch, upgrade, disable the vulnerable component, or apply vendor mitigations.
- Verify the running version after deployment, not only the package inventory.
Official and supporting references
- No vendor advisory tagged by NVD at draft time.