CVE-2026-93682 PHP Group CVE debrief

Who should care

Defenders responsible for configuring and securing HTTP stream wrappers should assess exposure and verify the affected product and vendor. They should also prioritize verifying the affected product and vendor, as well as implementing compensating controls to limit the impact of potential redirects. Additionally, defenders should review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance, and plan vendor-

Why it matters

A vulnerability in an unknown product allows a malicious server to control client redirects, potentially leading to security consequences. Defenders should prioritize verifying the affected product and vendor, as well as implementing compensating controls.

• A malicious server can control client redirects, potentially leading to security consequences
• Defenders need to verify the affected product and vendor to determine exposure
• Implementing compensating controls can limit the impact of potential redirects

Technical summary

The vulnerability occurs when the HTTP stream wrapper follows a redirect and the response carries a Location header with an empty value. This causes the redirect code to read one byte past the end of the heap buffer holding the location. The value of that out-of-bounds byte decides which redirect target is built, allowing a malicious server to control whether the client is sent to the host root or to the current directory.

Defensive priority

Defenders should prioritize verifying the affected product and vendor, as well as implementing compensating controls to limit the impact of potential redirects.

Recommended defensive actions

• Verify the affected product and vendor
• Implement compensating controls to limit the impact of potential redirects
• Monitor for potential exploitation attempts
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and NVD vulnerability detail page provide information about the vulnerability, but the affected product and vendor are unknown. The CVE Program record and NVD vulnerability detail page are the primary official records.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.