Score 7.3 from GitHub Security Advisory (severity: HIGH) published 2026-05-28. NVD baseline CVSS 7.3; sources differ by 0.0.
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
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.
May 28, 2026
June 1, 2026
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Showing the most recent 100 of 147 total refreshes for this CVE.
Explore the affected products and dependency analysis for CVE-2026-9658
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