CVE-2018-6334

highpriority · track · 40EPSS 0.019 · 80 %ileEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

1.91% (80th) EPSS

CVSS 7.5 · high

Is it mine?

9 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · nvd

EPSS · scored 2026-10-27

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).

cvss

Technical severity, 0–10. One row per scoring source.

9.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.5–9.8

v2.07.5highAV:N/AC:L/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 10 · impact 6.4

v3.09.8criticalCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 5.9

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · ENISA EU

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondaryexploitability 3.9 · impact 5.9

v3.19criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20USprimaryCWE-621US

affected products (9)

Products and version ranges known to be affected.

Facebook HHVM≤ 3.25.0enisa_euvdEU
Facebook HHVM≤ 3.24.6enisa_euvdEU
Facebook HHVM≤ 3.22.0enisa_euvdEU
Facebook HHVM≤ 3.21.10enisa_euvdEU
Facebook HHVM≤ 3.25.2enisa_euvdEU
Facebook HHVMunspecified → 3.21.10enisa_euvdEU
facebook hhvm≤ 3.21.9nvdUScpe:2.3:a:facebook:hhvm:*:*:*:*:*:*:*:*
facebook hhvm3.21.10 → 3.24.5nvdUScpe:2.3:a:facebook:hhvm:*:*:*:*:*:*:*:*
facebook hhvm3.24.6 → 3.25.1nvdUScpe:2.3:a:facebook:hhvm:*:*:*:*:*:*:*:*

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd NVD CVE.org MITRE

published 2018-12-31modified 2026-06-17

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+25188 more

references (6)

External citations — patches, advisories, analysis.

scry

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