CVE-2018-6345
The function number_format is vulnerable to a heap overflow issue when its second argument ($dec_points) is excessively large.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.75%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
The function number_format is vulnerable to a heap overflow issue when its second argument ($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).
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.75% probability · 78th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-122, CWE-787
- Affected
- facebook/hhvm
- Source
- cve-assign@fb.com
EPSS 1.7% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/facebook/hhvm/commit/190ffdf6c8b1ec443be202c7d69e63a7e3da25e3Patch, Third Party Advisory
- https://hhvm.com/blog/2019/01/14/hhvm-3.30.2.htmlRelease Notes, Vendor Advisory
- https://github.com/facebook/hhvm/commit/190ffdf6c8b1ec443be202c7d69e63a7e3da25e3Patch, Third Party Advisory
- https://hhvm.com/blog/2019/01/14/hhvm-3.30.2.htmlRelease Notes, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.