Various APC functions accept keys containing null bytes as input, leading to premature truncation of input. This issue affects HHVM versions prior to 3.30.12, all versions between 4.0.0 and 4.8.5, all versions between 4.9.0 and 4.23.1, as well as 4.24.0, 4.25.0, 4.26.0, 4.27.0, 4.28.0, and 4.28.1.
CVE-2019-11936
CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence
This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 0.6%, top 29% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 9.8Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 9.8
- EG Score
- 9.8(medium)
- EPSS
- 70.8%
- KEV
- Not listed
Published
December 4, 2019
Last Modified
November 21, 2024
Advisory Details (3)
Auto-updated Jun 29, 2026Upstream fix merged — awaiting tagged release. Sources: github_commit.
github_commit
commit f57df6d8cf33 (facebook/hhvm)
Fix landed in facebook/hhvm commit f57df6d8cf33 — awaiting tagged release
https://github.com/facebook/hhvm/commit/f57df6d8cf33cb14c40f52287da29360e7003373Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Frequently asked(5)
What is CVE-2019-11936?
CVE-2019-11936 is a critical vulnerability published on December 4, 2019. Various APC functions accept keys containing null bytes as input, leading to premature truncation of input. This issue affects HHVM versions prior to 3.30.12, all versions between 4.0.0 and 4.8.5, all versions between 4.9.0 and 4.23.1, as well as 4.24.0, 4.25.0, 4.26.0, 4.27.0, 4.28.0, and 4.28.1.
When was CVE-2019-11936 disclosed?
CVE-2019-11936 was first published in the National Vulnerability Database on December 4, 2019, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2019-11936 actively exploited?
CVE-2019-11936 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 70.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2019-11936?
CVE-2019-11936 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2019-11936?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2019-11936, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2019-11936
Is Your Infrastructure Affected by CVE-2019-11936?
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