CVE-2020-1918
HIGHDescription
In-memory file operations (ie: using fopen on a data URI) did not properly restrict negative seeking, allowing for the reading of memory prior to the in-memory buffer. This issue affects HHVM versions prior to 4.56.3, all versions between 4.57.0 and 4.80.1, all versions between 4.81.0 and 4.93.1, and versions 4.94.0, 4.95.0, 4.96.0, 4.97.0, 4.98.0.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Exploit Intelligence
Moderate risk: more likely to be exploited than 66% of all known CVEs.
References
Related Vulnerabilities
Other CWE-127 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2020-5360 | High | 7.5 | 2.2% | - | Fix |
| CVE-2025-32050 | Medium | 5.9 | 0.7% | - | Fix |
| CVE-2025-20359 | Medium | 6.5 | 0.4% | - | - |
| CVE-2026-5928 | High | 7.5 | 0.4% | - | Fix |
| CVE-2024-25629 | Medium | 4.4 | 0.3% | - | Fix |
| CVE-2024-10395 | High | 8.6 | 0.3% | - | - |
Common questions
How do I fix CVE-2020-1918?
Upgrade hhvm to 4.93.2 or later.
Is CVE-2020-1918 being actively exploited?
Not that we know of. CVE-2020-1918 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 1.2% is the estimated probability that it will be exploited in the next 30 days. That is higher than 66% of all scored CVEs.
How severe is CVE-2020-1918?
CVE-2020-1918 has a CVSS v3 base score of 7.5, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2020-1918 affect?
Published advisories record a fix for hhvm (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
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Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.