CVE detail

CVE-2020-1900 — CVE-2020-1900

Published 2021-03-11 · Modified 2026-06-17 · Vendor facebook · Product hhvm · Source nvd

CRITICAL

severity

CVSS-derived band

9.8

CVSS v3

0–10 scale

0.0138

EPSS probability

exploitation probability, 30d

70.0%

EPSS percentile

percentile vs all CVEs

NOT LISTED

CISA KEV

known exploited catalog

Description

When unserializing an object with dynamic properties HHVM needs to pre-reserve the full size of the dynamic property array before inserting anything into it. Otherwise the array might resize, invalidating previously stored references. This pre-reservation was not occurring in HHVM prior to v4.32.3, between versions 4.33.0 and 4.56.0, 4.57.0, 4.58.0, 4.58.1, 4.59.0, 4.60.0, 4.61.0, 4.62.0.

Remediation

No vendor-published fix data in our corpus for this CVE. Check the references below or the vendor's PSIRT / security advisories page.

References

cvedb.io · NVD · CISA KEV · FIRST EPSS · vendor advisories (CVE Program List v5). Informational only, no warranty — verify every remediation against the vendor advisory before acting on it. This product uses data from the NVD API but is not endorsed or certified by the NVD, CISA, FIRST.org or any vendor named. CVE® is a registered trademark of The MITRE Corporation.