CVE-2016-6871

CRITICAL

Integer overflow in bcmath in Facebook HHVM before 3.15.0 allows attackers to have unspecified impact via unknown vectors, which triggers a buffer overflow.

Affects 1 product across 1 vendor.

CVSS 3.09.8
EPSS2.3%
Percentile83th
PatchUnknown
CVSS Vector — Plain English Remotely exploitable over the network, low complexity, no authentication required, no user interaction needed, impact contained to the vulnerable component, full confidentiality impact, full integrity impact, full availability impact.
CWE Weakness Definitions
CWE-190: Integer Overflow or Wraparound

Arithmetic operation exceeds the maximum integer value, wrapping around and often leading to undersized allocations.

Related Attack Patterns (CAPEC)
CAPEC-92 Forced Integer Overflow
via CWE-190

Mapping is CWE-to-CAPEC per MITRE CAPEC 3.9.

◆ AI Analysis — automated analysis, not human-reviewed

This vulnerability was disclosed in 2017. A critical vulnerability affects Facebook systems (CVE-2016-6871). No public exploit code is currently available. Isolate affected systems if patching is not feasible.

BSID: BS-2017-GLOBAL-111999-C • Model: rule-based-v1 • Confidence: MEDIUM

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Frequently Asked Questions
What is CVE-2016-6871?
This vulnerability was disclosed in 2017. A critical vulnerability affects Facebook systems (CVE-2016-6871). No public exploit code is currently available. Isolate affected systems if patching is not feasible.
What is the CVSS score for CVE-2016-6871?
CVE-2016-6871 has CVSS 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS: 2.3%.
Is CVE-2016-6871 actively exploited?
No confirmed active exploitation of CVE-2016-6871 as of 2026-09-25.
How do I remediate CVE-2016-6871?
Priority: MEDIUM.
What systems are affected by CVE-2016-6871?
CVE-2016-6871 affects Facebook Hhvm.
Vulnerability Details
CVE IDCVE-2016-6871
BSIDBS-2017-GLOBAL-111999-C BreachSpider Global ID
CVSS VectorCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published2017-02-17
Last Modified2026-06-17
ICS Relevance0%
Weakness (CWE)
Integer Overflow or Wraparound
SourceNVD
Official Description

Integer overflow in bcmath in Facebook HHVM before 3.15.0 allows attackers to have unspecified impact via unknown vectors, which triggers a buffer overflow.

Source: NIST NVD / MITRE CVE Database

Attack Vector Analysis — CITED Relevance

Vulnerability details: Integer overflow in bcmath in Facebook HHVM before 3.15.0 allows attackers to have unspecified impact via unknown vectors, which triggers a buffer overflow. CVSS vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Exploitation Likelihood: LOW

Affected Products
VendorProductAffected Versions
Facebook Hhvm ≤ 3.14.5
Remediation

No official vendor advisory link on record. See the CVE record →

Threat Intelligence
● Threat Intelligence Validated: October 2026 | Threat Age: 3527 Days
CISA known-exploitedNot in KEV catalog
Public ExploitNot confirmed
PoC CodeNot confirmed
AI Enrichment Record — provenance & audit hash
Modelrule-based-v1
ConfidenceMEDIUM
Enriched At2026-05-24
SHA-512 Audit Hash2162b7e5f06f05351a5bb21f27521fd6fdf5d673c224d927c26be142cf8a54c311546d11c2779207b575d81043d5dc1e36516466e63f72d8dbc8b5c89f155678
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