CVE-2020-1900

CriticalCVSS 9.8/10Last modified Jun 17, 2026

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.

Metrics

CVSS 3.1 9.8/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness enumeration

Affected software

No affected versions have been published.

Timeline

Published
Mar 11, 2021
Last modified
Jun 17, 2026
NVD status
Modified

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CVE-2020-1900: Critical severity, CVSS 9.8 | Vulnix