PatchTheCVECVE-2026-17552: Plack::App::Prerender versions before 0.3.0 for Perl can proxy to an arbitrary host via unvalidated REQUEST_UR
CVE-2026-17552 is a critical-severity flaw (CVSS 9.1) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Plack::App::Prerender versions before 0.3.0 for Perl can proxy to an arbitrary host via unvalidated REQUEST_URI concatenation in call. When the rewrite base is a plain string, the REQUEST_URI is appended to it, with no check that the path starts with a forward slash ('/'). When the rewrite base does not contain a path (which is the standard given in the SYNOPSIS), an attacker can create a request that changes the hostname. A request target star
Why this priority
- Critical severity
- CISA SSVC: automatable with total technical impact
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.1 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.5% (top 55%) |
| CISA exploited list | No |
| Weakness | CWE-918 |
| Published | 2026-07-27 |
| Last modified | 2026-10-24 |
Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-17552?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-17552 being exploited?
CVE-2026-17552 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-17552 affect?
CVE-2026-17552 affects affected software. Severity is critical (CVSS 9.1). Plack::App::Prerender versions before 0.3.0 for Perl can proxy to an arbitrary host via unvalidated REQUEST_URI concatenation in call. When the rewrite base is a plain string, the REQUEST_URI is appended to it, with no check that the path
How urgent is CVE-2026-17552?
Priority 51/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action