CVE-2026-126380: CVE-2026-126380: Vvveb before 1.0.9.0 contains a denylist bypass in system/traits/media.php where '.phar' i…
Unknown · Vvveb · NVD published 2026-11-13 · posted 2026-11-13 · last modified 2026-11-13
CVE-2026-126380 at a glance
CVE-2026-126380 is a critical-severity File Upload vulnerability in Vvveb, with a CVSS 4.0 base score of 9.4. NVD published it on 2026-11-13 and classifies the weakness as CWE-434. FIRST EPSS puts the probability of exploitation activity in the next 30 days at 0.55% (percentile 46.6, scored 2026-11-14). NVD does not list a fixed version, so the vendor advisory is the reference for the fix. CVERadar maps 3 MITRE ATT&CK techniques across Initial Access, Persistence and Execution, inferred from the CWE and the description. Its CVERadar threat level is 47/100.
What it is
Vvveb before 1.0.9.0 contains a denylist bypass in system/traits/media.php where '.phar' is misconfigured with a leading dot, allowing authenticated administrators to upload .phar PHP files. Attackers can upload a GIF magic-byte polyglot webshell bypassing binary inspection and execute arbitrary OS commands as the web-server user.
| Weakness | CWE-434 definition |
|---|---|
| CVSS vector | CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X (source: VulnCheck) |
| ATT&CK tactics | Initial Access → Execution → Persistence |
Defend the Chain
The attack chain for CVE-2026-126380 laid across the MITRE ATT&CK Enterprise tactics. Solid cards come from the MITRE CTID KEV mappings; dashed cards are inferred by CVERadar from the CWE or description. Correct defences are real ATT&CK mitigations for that technique.
Pick a red technique card on the board, then choose the defence that stops it.
Defend against T1190 Exploit Public-Facing Application Inferred
Inferred from CWE CWE-434
Patches, mitigations and detection
Fixed versions
NVD does not list a fixed version for this CVE. Use the vendor advisory below.
Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.
Vendor advisories and patches
No vendor-tagged reference yet; see the full reference list.
MITRE ATT&CK mitigations for this chain
- M1048 Application Isolation and Sandboxing (for T1190) : Application isolation will limit what other processes and system features the exploited target can access.
- M1037 Filter Network Traffic (for T1190) : Restrict outbound network traffic from public-facing servers to prevent unauthorized connections from initiating communications with attacker-controlled infrastructure. While this may not prevent the initial exploitation, it limits the attacker's ability to verify and control the compromised server post-exploit, reduci
- M1030 Network Segmentation (for T1190) : Segment externally facing servers and services from the rest of the network with a DMZ or on separate hosting infrastructure.
- M1016 Vulnerability Scanning (for T1190) : Regularly scan externally facing systems for vulnerabilities and establish procedures to rapidly patch systems when critical vulnerabilities are discovered through scanning and through public disclosure.
- M1026 Privileged Account Management (for T1190, T1059) : Use least privilege for service accounts will limit what permissions the exploited process gets on the rest of the system.
- M1050 Exploit Protection (for T1190) : Web Application Firewalls may be used to limit exposure of applications to prevent exploit traffic from reaching the application.
- M1035 Limit Access to Resource Over Network (for T1190) : Ensure that all publicly exposed services are actually intended to be so, and restrict access to any that should only be available internally.
- M1051 Update Software (for T1190) : Update software regularly by employing patch management for externally exposed applications.
- M1033 Limit Software Installation (for T1059) : Prevent user installation of unrequired command and scripting interpreters.
- M1045 Code Signing (for T1059) : Where possible, only permit execution of signed scripts.
Detection Generic guidance
- Initial Access: Alert on unusual requests to the affected service (odd paths, oversized payloads, exploit strings) in WAF, reverse-proxy and application logs.
- Execution: Watch for the service process spawning shells or script interpreters (cmd.exe, powershell, sh, bash, python) via EDR process-tree rules.
- Persistence: Look for new files in web roots, new scheduled tasks/services, and new accounts created after the exposure window.
Response checklist Generic guidance
- Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
- Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
- Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
- Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.
Before patching, it helps to know every exposed instance; external attack surface monitoring from LayerLogix does that inventory.
Sources
- NVD: CVE-2026-126380
- CVE.org record for CVE-2026-126380
- FIRST EPSS score for CVE-2026-126380 (2026-11-14)
- GitHub fix commit (github.com) github.com/givanz/Vvveb/commit/638a6c6f5a7a7f7ff4c65f996894f400d8fb8e77
- GitHub security advisory (github.com) github.com/givanz/Vvveb/security/advisories/GHSA-hcpj-pcpx-2744
- VulnCheck reference (vulncheck.com) vulncheck.com/advisories/vvveb-before-1.0.9.0-rce-via-phar-extension-denylist-by