CVE-2018-6345 json
The function number_format is vulnerable to a heap overflow issue when its second argument ($dec_points) is excessively large.
published 2019-01-15 7 y ago modified 2026-06-17 4 mo ago also EUVD-2018-18103
- cvss
- 9.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.7%
- EPSS 1.7% chance of exploitation in 30 days, percentile 77%
- public exploits
- 0
- none known
Summary
The function number_format is vulnerable to a heap overflow issue when its second argument ($dec_points) is excessively large. The internal implementation of the function will cause a string to be created with an invalid length, which can then interact poorly with other functions. This affects all supported versions of HHVM (3.30.1 and 3.27.5 and below).
Patch / fix
Exploit prediction
1.75% chance of exploitation in the next 30 days, higher than 77% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P |
Affected products
- Facebook HHVM
Classification
References
-
github.com
/facebook/hhvm/commit/190ffdf6c8b1ec443be202c7d69e63a7e3da25e3
patch, third-party-advisory
-
hhvm.com
/blog/2019/01/14/hhvm-3.30.2.html
release-notes, vendor-advisory
Sources
- CVE List CVE-2018-6345
- NVD CVE-2018-6345
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.