CVE-2020-9490

CVE-2020-9490 is a high-severity vulnerability in Apache Http Server with a CVSS 3.x base score of 7.5. Its EPSS exploit-prediction score of 90% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-444.

Key facts

Description

Apache HTTP Server versions 2.4.20 to 2.4.43. A specially crafted value for the 'Cache-Digest' header in a HTTP/2 request would result in a crash when the server actually tries to HTTP/2 PUSH a resource afterwards. Configuring the HTTP/2 feature via "H2Push off" will mitigate this vulnerability for unpatched servers.

Frequently asked questions

What is CVE-2020-9490?
Apache HTTP Server versions 2.4.20 to 2.4.43. A specially crafted value for the 'Cache-Digest' header in a HTTP/2 request would result in a crash when the server actually tries to HTTP/2 PUSH a resource afterwards. Configuring the HTTP/2 feature via "H2Push off" will mitigate this vulnerability for unpatched servers.
How severe is CVE-2020-9490?
CVE-2020-9490 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-9490 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 90% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-9490?
CVE-2020-9490 primarily affects Apache Http Server. In total, 50 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-9490?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-9490 published?
CVE-2020-9490 was published on 2020-08-07 and last updated on 2026-06-17.

References

Affected products (50)

More vulnerabilities in Apache Http Server

All CVEs affecting Apache Http Server →

Other CWE-444 (HTTP Request/Response Smuggling) vulnerabilities

Browse all CWE-444 (HTTP Request/Response Smuggling) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE: