Memory corruption in Meta HHVM
Priority MEDIUM 42CWE-212Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA.
Summary
folly::secureRandom will re-use a buffer between parent and child processes when fork() is called. That will result in multiple forked children producing repeat (or similar) results. This affects HHVM 3.26 prior to 3.26.3 and the folly library between v2017.12.11.00 and v2018.08.09.00.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01778 78th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Meta | HHVM | 3.26.3; 3.26.0 and later | — | No fix listed | CNA |
| Meta | folly | v2018.08.09.00; v2017.12.11.00 and later | — | No fix listed | CNA |
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2018-6337
- 2026-10-03 Alias added: GHSA-46jm-3g2r-j53x
References
More Meta Folly vulnerabilities
- TI-2021-06352 Heap-based buffer overflow in Meta folly CVSS 3.1CRITICAL 9.8
- TI-2019-08939 Out-of-bounds read in Meta folly CVSS 3.1CRITICAL 9.8
Sources
- CVE-2018-6337 · CVE Program
- CVE-2018-6337 · NVD
- FIRST EPSS
- GHSA-46jm-3g2r-j53x · GitHub Advisory Database · CC BY 4.0
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