VulnerabilityPublished 27 Jul 2026

CVE-2026-17552: RRWO Plack::App::Prerender · Server-Side Request Forgery (SSRF)

Affects RRWO Plack::App::PrerenderSource CVE Database V5

Not known to be exploited · CVSS 9.1 Critical : upgrade to 0.3.0 as a priority.

Data as of 27 Oct 2026, 05:11 UTC

CVSS 3.1 base score

9.1Critical

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.5% chance of exploitation in 30 days – higher than 45% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.3.0

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 27 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Plack::App::Prerender and Plack-App-Prerender to 0.3.0.

Affected software

Product	Affected	Fixed in
RRWOPlack::App::Prerender	Affected <0.3.0	Fixed in 0.3.0
GitHubPlack-App-Prerender`pkg:github/Plack-App-Prerender`Other threats	Affected <0.3.0	Fixed in 0.3.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

If you cannot patch yet, users should avoid using affected versions (<0.3.0) of Plack::App::Prerender or implement strict input validation to ensure that the REQUEST_URI cannot be manipulated to alter the hostname. Monitoring for updates from the vendor or CPAN security advisories is recommended.

Description

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 starting with an at-sign ('@') changes the base to a RFC 3986 userinfo component. For example, a rewrite base of "https://example.com" with the submitted request "GET @192.168.1.2/" will send a request to "https://example.com@192.168.1.2/", with the rendered content returned to the attacker. This allows an attacker to access internal or restricted hosts that only the webserver has access to.

Impact

This vulnerability enables an unauthenticated attacker to perform SSRF attacks, potentially accessing internal or restricted hosts that are otherwise inaccessible externally. The attacker can retrieve content from these internal resources via the vulnerable proxy, leading to confidentiality breaches. The CVSS score of 9.1 reflects high impact on confidentiality and integrity without affecting availability.

Summary

Plack::App::Prerender versions prior to 0.3.0 contain an SSRF vulnerability due to improper validation of the REQUEST_URI when concatenated with the rewrite base URL. If the rewrite base is a plain string without a path, an attacker can craft a request starting with an '@' character, which modifies the hostname portion of the URL to include arbitrary hosts. For example, a rewrite base of "https://example.com" combined with a request "GET @192.168.1.2/" results in a request to "https://example.com@192.168.1.2/", effectively allowing the attacker to access internal hosts through the proxy functionality of the application.

CWE-918Server-Side Request Forgery (SSRF) (opens in a new tab)
Base weaknessCWE Top 25 (2025): #22OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
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.
OWASP Cheat Sheets
Server Side Request Forgery Prevention (opens in a new tab)
Unvalidated Redirects and Forwards (opens in a new tab)
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.6.1 (opens in a new tab)
V5.2.6 (opens in a new tab)
Attack patterns
Server Side Request Forgery (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 29 Jul 2026, 23:51 UTC

WeaknessesCWE-918

Technical details

References

Community reviews

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