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Vulnerabilities

Vulnerability · CVE-2026-9658

Plack::Middleware::Security::Common versions before 0.13.1 for Perl did not block header injections in request paths.

Published May 28, 2026 · catalog updated Jun 17, 2026 · Plack::Middleware::Security::Common versions before 0.13.1

Check if you run it

No confirmed exploitation is on record for CVE-2026-9658. EPSS is 0.34%. Act only if a listed version of Plack::Middleware::Security::Common versions before 0.13.1 is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Plack::Middleware::Security::Common versions before 0.13.1).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.3
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.34%
Remediation
Advisory link
Affected products
See sources for product scope

Plack::Middleware::Security::Common versions before 0.13.1 for Perl did not block header injections in request paths. The header injection rule was ineffective at blocking header injections in the request paths unless they were double-encoded, for example, GET /path\r\nHTTP/1.1\r\nHost: secret.example.com Note that it is unclear whether request paths with CRLF followed by additional headers would be blocked by reverse proxies, or how they would be processed by Plack-based servers.

No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.

How to fix CVE-2026-9658

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-9658. EPSS is 0.34%. Act only if a listed version of Plack::Middleware::Security::Common versions before 0.13.1 is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-113; CWE-790. EPSS 0.34%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. May 28, 2026 · NIST NVD

    Detected

    Plack::Middleware::Security::Common versions before 0.13.1 for Perl did not block header injections in request paths. The header injection rule was ineffective at blocking header injections in the request paths unless they were double-encoded, for example, GET /path\r\nHTTP/1.1\r\nHost: secret.example.com Note that it is unclear whether request paths with CRLF followed by additional headers would

  2. Jun 17, 2026 · NIST NVD

    Updated

    Plack::Middleware::Security::Common versions before 0.13.1 for Perl did not block header injections in request paths. The header injection rule was ineffective at blocking header injections in the request paths unless they were double-encoded, for example, GET /path\r\nHTTP/1.1\r\nHost: secret.example.com Note that it is unclear whether request paths with CRLF followed by additional headers would

Sources

  • CVE.orgVulnerability recordCVE-2026-9658

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-9658

    30-day exploitation probability 0.3%

    first.org
  • NIST NVDVulnerability recordCVE-2026-9658

    Plack::Middleware::Security::Common versions before 0.13.1 for Perl did not block header injections in request paths. The header injection rule was ineffective at blocking header injections in the request paths unless they were double-encoded, for example, GET /path\r\nHTTP/1

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.