CVE-2023-36478: Debian Linux

High severity, CVSS 7.5. EPSS: 3.8% chance of exploitation in the next 30 days.

Eclipse Jetty provides a web server and servlet container. In versions 11.0.0 through 11.0.15, 10.0.0 through 10.0.15, and 9.0.0 through 9.4.52, an integer overflow in `MetaDataBuilder.checkSize` allows for HTTP/2 HPACK header values to exceed their size limit. `MetaDataBuilder.java` determines if a header name or value exceeds the size limit, and throws an exception if the limit is exceeded. However, when length is very large and huffman is true, the multiplication by 4 in line 295 will overflow, and length will become negative. `(_size+length)` will now be negative, and the check on line 296 will not be triggered. Furthermore, `MetaDataBuilder.checkSize` allows for user-entered HPACK header value sizes to be negative, potentially leading to a very large buffer allocation later on when the user-entered size is multiplied by 2. This means that if a user provides a negative length value (or, more precisely, a length value which, when multiplied by the 4/3 fudge factor, is negative), and this length value is a very large positive number when multiplied by 2, then the user can cause a very large buffer to be allocated on the server. Users of HTTP/2 can be impacted by a remote denial of service attack. The issue has been fixed in versions 11.0.16, 10.0.16, and 9.4.53. There are no known workarounds.

Affected products

• Debian Debian Linux: version 10.0 only; version 11.0 only; version 12.0 only
• Eclipse Jetty: from 9.3.0, before 9.4.53 (fixed in 9.4.53); from 10.0.0, before 10.0.16 (fixed in 10.0.16); from 11.0.0, before 11.0.16 (fixed in 11.0.16)
• Jenkins Jenkins: before 2.414.3 (fixed in 2.414.3); before 2.428 (fixed in 2.428)

Published 2023-10-10. Last modified 2026-06-17.