What’s Vulnerable › Vulnerabilities

CVE-2020-1893

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-03-03 · updated 2026-06-17
• Weakness: CWE-125

Description

Insufficient boundary checks when decoding JSON in TryParse reads out of bounds memory, potentially leading to DOS. This issue affects HHVM 4.45.0, 4.44.0, 4.43.0, 4.42.0, 4.41.0, 4.40.0, 4.39.0, versions between 4.33.0 and 4.38.0 (inclusive), versions between 4.9.0 and 4.32.0 (inclusive), and versions prior to 4.8.7.

Affected products

• Facebook HHVM: before 4.8.7; from 4.9.0 through 4.32.0; from 4.33.0 through 4.38.0; 4.39.0, 4.40.0, 4.41.0, 4.42.0, 4.43.0, 4.44.0 (+1) — fixed in 4.8.7

How to fix

Upgrade to a fixed version: Facebook HHVM 4.8.7. Check the vendor advisory for mitigations.

References

• https://github.com/facebook/hhvm/commit/bd586671a3c22eb2f07e55f11b3ce64e1f7961e7
• https://hhvm.com/blog/2020/02/20/security-update.html
• https://github.com/facebook/hhvm/commit/bd586671a3c22eb2f07e55f11b3ce64e1f7961e7
• https://hhvm.com/blog/2020/02/20/security-update.html

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