EXECUTIVE SUMMARY:
A high-severity memory exhaustion flaw has been identified in the request-handling mechanisms of popular web server software, potentially allowing remote attackers to induce a denial-of-service state. This vulnerability poses a significant risk as it bypasses resource protection mechanisms without requiring authentication, leaving unpatched infrastructure vulnerable to service disruption. By weaponizing specific protocol behaviors, malicious actors can systematically deplete system memory, preventing the processing of legitimate requests. A public proof-of-concept exploit script has been made available, heightening the urgency for administrators to apply remediations to vulnerable deployments. CVE-2026-49975: This vulnerability manifests within the HTTP/2 request-handling path due to a failure to properly count merged cookie header fields against standard restriction limits. Remote attackers can exploit this by transmitting a small, HPACK-encoded request that decompresses into an excessive number of fields, forcing repeated memory allocation. By concurrently manipulating flow control mechanisms to hold streams open, the server is prevented from releasing this memory, creating a sustained exhaustion condition. This leads to a complete remote denial of service, forcing the web server offline without requiring any privileged access or credentials.[/subscribe_to_unlock_form]
EXECUTIVE SUMMARY:
A high-severity memory exhaustion flaw has been identified in the request-handling mechanisms of popular web server software, potentially allowing remote attackers to induce a denial-of-service state. This vulnerability poses a significant risk as it bypasses resource protection mechanisms without requiring authentication, leaving unpatched infrastructure vulnerable to service disruption. By weaponizing specific protocol behaviors, malicious actors can systematically deplete system memory, preventing the processing of legitimate requests. A public proof-of-concept exploit script has been made available, heightening the urgency for administrators to apply remediations to vulnerable deployments. CVE-2026-49975: This vulnerability manifests within the HTTP/2 request-handling path due to a failure to properly count merged cookie header fields against standard restriction limits. Remote attackers can exploit this by transmitting a small, HPACK-encoded request that decompresses into an excessive number of fields, forcing repeated memory allocation. By concurrently manipulating flow control mechanisms to hold streams open, the server is prevented from releasing this memory, creating a sustained exhaustion condition. This leads to a complete remote denial of service, forcing the web server offline without requiring any privileged access or credentials.[emaillocker id="1283"]
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The following reports contain further technical details:
https://cybersecuritynews.com/http-2-bomb-dos-apache/