CVE-2026-85733 — FrankenPHP: Docker images serve phpinfo() as the default index.php, leaking environment variables
FrankenPHP is a modern application server for PHP. Prior to 1.12.5, the official FrankenPHP Debian and Alpine Docker images include a default /app/public/index.php that executes phpinfo(). A derived image that does not overwrite this placeholder serves the diagnostics page in production and can disclose environment variables used for secrets, PHP configuration directives, loaded extensions, software versions, and system paths. Images built using the documented pattern with their own /app/public/index.php are not affected, and already derived images must be rebuilt or supplied with an application index to remove the exposed placeholder. This issue is fixed in version 1.12.5.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+2
- Technical severity (medium)+3
- Automatable exploitation (SSVC)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Php Frankenphp).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (info disclosure), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Php | Frankenphp | version < 1.12.5 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 5.3 | CVSS 3.1 | Medium | 3.9 | 1.4 | security-advisories@github.com via NIST National Vulnerability Database |
| 5.3 | CVSS 3.1 | Medium | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Look for anomalous data read/export volumes and access to sensitive records.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · php/frankenphp
- SSVC assessment updated
- Record published
- CVSS changed · 5.3
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
4 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-82416 FrankenPHP: Cross-request PHP session ID leak in worker mode when the session extension is a shared module 2d
- High CVE-2026-45062 FrankenPHP: Unsafe Unicode Handling in CGI Path Splitting Allows Execution of Non-PHP Files Jun 10, 2026
- High CVE-2026-24894 FrankenPHP leaks session data between requests in worker mode Feb 12, 2026
- Critical CVE-2026-24895 FrankenPHP affected by Path Confusion via Unicode casing in CGI path splitting allows execution of arbitrary files Feb 12, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-85733 is "FrankenPHP: Docker images serve phpinfo() as the default index.php, leaking environment variables", rated Medium. It affects Frankenphp (Php); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.3 describes technical severity. EPSS 0.24% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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