Description

In OpenStack Swift before 2.36.2 and 2.37.2, s3api middleware enters an infinite loop when processing a truncated aws-chunked PUT request body. The StreamingInput class repeatedly appends an empty buffer and re-reads, causing the proxy-server worker handling the request to become permanently unresponsive with increasing CPU and memory consumption. An authenticated attacker can systematically exhaust all proxy-server workers, resulting in denial of service. The defect was introduced in Swift 2.36.0.

Dates

Published: 2026-05-27 · Last Modified: 2026-06-02

Weaknesses

References

• https://bugs.launchpad.net/bugs/2152205
• https://review.opendev.org/c/openstack/swift/+/987957
• https://review.opendev.org/c/openstack/swift/+/988093
• http://www.openwall.com/lists/oss-security/2026/05/27/9
• http://www.openwall.com/lists/oss-security/2026/06/02/6