mcrypt_get_block_size did not enforce that the provided "module" parameter was a string, leading to type confusion if other types of data were passed in. This issue affects HHVM versions prior to 3.9.5, all versions between 3.10.0 and 3.12.3 (inclusive), and all versions between 3.13.0 and 3.14.1 (inclusive).
Conclusion & alert: CVE-2016-1000005 is rated Moderate Risk (64.1/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 1.39%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.53% | 1.39% | +0.86% |
| 2 | 2025-12-28 | 0.43% | 0.53% | +0.10% |
| 3 | 2025-12-27 | — | 0.43% | — |
Full EPSS history (11 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.8 | 3.1 | CRITICAL |
|
3.9 | 5.9 | [email protected] |
| 7.5 | 2.0 | HIGH |
|
10.0 | 6.4 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
ubuntu
|
low | CVE-2016-1000005 low priority: Ubuntu including 1 source packages (hhvm), 23 status rows across 23 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, precise, questing, trusty, upstream, xenial, yakkety, zesty): DNE 18, not-affected 3, needed 1, released 1. | https://ubuntu.com/security/CVE-2016-1000005 |
| URL | Tags |
|---|---|
| https://github.com/facebook/hhvm/commit/39e7e177473350b3a5c34e8824af3b98e25efa89 | Patch Third Party Advisory |
| https://www.facebook.com/security/advisories/cve-2016-1000005 | Third Party Advisory |