Read the docs
TI-2018-04659 Aliases CVE-2018-6334GHSA-v7mg-wg5h-pcx8

Improper input validation in Meta HHVM

Priority MEDIUM 53CWE-621Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA.

Summary

Multipart-file uploads call variables to be improperly registered in the global scope. In cases where variables are not declared explicitly before being used this can lead to unexpected behavior. This affects all supported versions of HHVM prior to the patch (3.25.1, 3.24.5, and 3.21.9 and below).

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01913 79th percentileScored 2026-11-07
Fix Fixed HHVM (Facebook): 3.21.10

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MetaHHVM3.25.2; 3.25.0; 3.24.6; 3.22.0; 3.21.10; before 3.21.103.21.10Patch availableCNA
  • HHVM VendorMeta Affected 3.25.2; 3.25.0; 3.24.6; 3.22.0; 3.21.10; before 3.21.10 Fixed in 3.21.10 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:facebook:hhvm:*:*:*:*:*:*:*:*up to 3.21.9; 3.21.10 – 3.24.5; 3.24.6 – 3.25.1VulnerableMeta
  • cpe:2.3:a:facebook:hhvm:*:*:*:*:*:*:*:* Versions up to 3.21.9; 3.21.10 – 3.24.5; 3.24.6 – 3.25.1 Vulnerable ·Meta

Remediation

  • Fix · CNA HHVM (Facebook) Fixed in 3.21.10

Timeline

  1. 2026-10-02 Threatist record created from CVE-2018-6334
  2. 2026-10-03 Alias added: GHSA-v7mg-wg5h-pcx8

References

Patch 2

  • TI-2022-17147 Broken or risky cryptographic algorithm in Meta HHVM CVSS 3.1CRITICAL 9.8
  • TI-2019-08934 Memory corruption in Meta HHVM CVSS 3.1CRITICAL 9.8
  • TI-2021-06352 Heap-based buffer overflow in Meta folly CVSS 3.1CRITICAL 9.8
  • TI-2019-08935 An invalid free in mb_detect_order can cause the application to crash or potentially… CVSS 3.1CRITICAL 9.8
  • TI-2016-05898 Integer overflow in bcmath in Facebook HHVM before 3.15.0 allows attackers to have… CVSS 3.0CRITICAL 9.8
  • TI-2019-08931 Memory corruption in Meta HHVM CVSS 3.0CRITICAL 9.8
See all 39 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences