Security readout for executives and security teams
Plain-English summary
A flaw in Phalcon’s Volt template compiler can turn attacker-controlled template content into executable PHP. Successful exploitation could compromise application data, integrity, and availability. The attacker must be able to influence Volt template source; ordinary user input is not automatically sufficient. Phalcon 5.16.0 fixes the issue.
Executive priority
Treat affected systems with attacker-influenced templates as an urgent patching priority because compromise could provide application-level code execution. Quickly establish whether template source is externally controllable; that condition materially changes immediate risk. Upgrade exposed systems to 5.16.0 or later after normal change validation.
Technical view
Before 5.16.0, Volt’s resolveFilter builds the join filter using raw separator and array tokens instead of processing them through expression(). Quote-breaking template content can therefore inject PHP into the compiled template cache, which executes when Volt renders the template. The issue is classified as CWE-1336 and CWE-94, with CVSS 4.0 score 9.2.
Likely exposure
Exposure is highest for internet-facing applications running cphalcon below 5.16.0 where users, integrations, administrators, or content workflows can modify or generate Volt template source. Applications using only trusted, immutable templates have a substantially narrower attack path. The supplied sources do not identify specific deployed products or organizations.
Exploitation context
The supplied record is not in KEV and provides no evidence of active exploitation. Exploitation requires influence over Volt template source, but then needs no privileges or user interaction according to the supplied CVSS vector. Successful injection executes in the application’s PHP runtime context.
Researcher notes
The vulnerable sink is join-filter code generation inside Volt Compiler.resolveFilter. Raw separator and array token insertion permits compile-time PHP injection, followed by execution when the cached template is loaded. The attack precondition is template-source influence. The supplied sources establish the fix and affected range but do not establish exploitation in the wild.
Mitigation direction
- Upgrade Phalcon cphalcon to version 5.16.0 or later.
- Prevent untrusted users or data pipelines from modifying or generating Volt template source.
- Review the vendor advisory and release notes for deployment-specific guidance.
- Prioritize systems where templates are editable through public, tenant, CMS, or integration workflows.
Validation and detection
- Inventory applications and confirm their installed cphalcon versions.
- Identify every workflow capable of creating or modifying Volt templates.
- Confirm untrusted request data cannot become Volt template source.
- Review compiled template caches and application logs for unexpected PHP behavior.
- Retest template rendering after upgrading to version 5.16.0 or later.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-1336: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-94: Code execution behavior lookup
Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-59989 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.2 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——GitHub_MVulnerability scoring details
Base CVSS 4.0 score
9.2CriticalVector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/phalcon/cphalcon/security/advisories/GHSA-hrwp-4hh9-c8r8CVE reference, GitHub_M · x_refsource_CONFIRM
- https://github.com/phalcon/cphalcon/pull/17217CVE reference, GitHub_M · x_refsource_MISC
- https://github.com/phalcon/cphalcon/commit/e434061be3b7161930476c1368c868badc71e1bdCVE reference, GitHub_M · x_refsource_MISC
- https://github.com/phalcon/cphalcon/releases/tag/v5.16.0CVE reference, GitHub_M · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Special Elements Used in a Template Engine
Improper Neutralization of Special Elements Used in a Template Engine represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Improper Control of Generation of Code
Improper Control of Generation of Code represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.