CVE-2020-1900
highpriority · track · 39EPSS 0.014 · 72 %ileEUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.5–9.8
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (17)
Products and version ranges known to be affected.
also known as (3)
Other names and identifiers for this entity.
sources
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references (7)
External citations — patches, advisories, analysis.
- https://github.com/facebook/hhvm/commit/c1c4bb0cf9e076aafaf4ff3515556ef9faf906f3cnnvd
- https://hhvm.com/blog/2020/06/30/security-update.htmlcnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2020-1900cnnvd
- https://github.com/facebook/hhvm/commit/c1c4bb0cf9e076aafaf4ff3515556ef9faf906f3enisa_euvd
- https://hhvm.com/blog/2020/06/30/security-update.htmlenisa_euvd
- https://github.com/facebook/hhvm/commit/c1c4bb0cf9e076aafaf4ff3515556ef9faf906f3PatchThird Party Advisorynvd
- https://hhvm.com/blog/2020/06/30/security-update.htmlVendor Advisorynvd
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