Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2018-6334

30
FAUCET Score

CVE-2018-6334 is a critical vulnerability affecting all supported versions of HHVM prior to 3.25.1, 3.24.5, and 3.21.9. It stems from improper registration of variables in the global scope during multipart-file uploads, leading to unexpected behavior when variables are not explicitly declared. With a CVSS score of 9.8 (CRITICAL), this vulnerability is easily exploitable over the network with low complexity, allowing for complete compromise of confidentiality, integrity, and availability. Despite its severity, there is no public exploit code available, no evidence of active exploitation, and minimal community discussion or media coverage.

Impacted Technologies

VendorProductVersion(s)CPE
<= 3.21.9CPE matchmatch criteria
cpe:2.3:a:facebook:hhvm:*:*:*:*:*:*:*:*
>= 3.21.10, <= 3.24.5CPE matchmatch criteria
cpe:2.3:a:facebook:hhvm:*:*:*:*:*:*:*:*
>= 3.24.6, <= 3.25.1CPE matchmatch criteria
cpe:2.3:a:facebook:hhvm:*:*:*:*:*:*:*:*
< 3.21.10CPE match
cpe:2.3:a:facebook:hhvm:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.0

9.8CRITICAL

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
5.9
CvssVersion
3.0

Exploit Intelligence

EPSS Score
1.91%
Probability of exploitation in next 30 days
EPSS Percentile
77.7%
Percentile rank of EPSS score among Peer Group
As of 2026-07-25
Model: v2026.06.15
This CVE's current EPSS score of 0.0191 is in the 66th percentile among its peer group of 36,833 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (1)

github_advisorypatch availablevia nvd_reference
View patch

References

github.com / facebook/hhvm/commit/6937de5544c3eead3466b75020d8382080ed0cff
PatchThird Party Advisory
hhvm.com / blog/2018/03/30/hhvm-3.25.2.html
PatchThird Party Advisory