Back to Database
Status published
High
CVE-2020-1899
The unserialize() function supported a type code, "S", which was...
Vulnerability Description
The unserialize() function supported a type code, "S", which was meant to be supported only for APC serialization. This type code allowed arbitrary memory addresses to be accessed as if they were static StringData objects. This issue affected 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.
Impact Analysis
Refer to official advisory for detailed impact metrics.
Remediation
Ensure systems are updated to the latest vendor-supplied patch levels.
THREAT MONITOR
Am I Vulnerable?
Launch our assessment wizard to check if your infrastructure is exposed to • CVE-2020-1899
Credits & Attribution
No credits recorded in the NVD database.
References
More from Facebook
View All →CVE-2025-64296
WordPress Facebook for WooCommerce plugin <= 3.5.7 - Broken Access Control to Notice Dismissal vulnerability
Medium
5.3
CVE-2025-55181
Sending an HTTP request/response body with greater than 2^31 bytes...
Medium
5.3
CVE-2025-55179
Incomplete validation of rich response messages in WhatsApp for iOS...
Medium
5.4
CVE-2025-55177
Incomplete authorization of linked device synchronization messages in WhatsApp for...
Medium
5.4
CVE-2025-30403
A heap-buffer-overflow vulnerability is possible in mvfst via a specially...
Unknown
0
Affected Vendor
Affected Software
HHVM
Vulnerable Versions:
4.62.1, 4.62.0, 4.61.1, 4.61.0, 4.60.1, 4.60.0, 4.59.1, 4.59.0, 4.58.2, 4.58.0, 4.57.1, 4.57.0, 4.56.1, 4.33.0, 4.32.3, unspecified
Timeline
Official Publish:
March 11th, 2021
Last Modified:
August 4th, 2024
Added to House:
July 21st, 2026
CVSS Vectors
V3:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N