CVE-2026-49017

What it is

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.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of service disruption.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-05-27 02:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-24 17:25 UTC Last updatedMost recent change to the record

Details

Published

2026-05-27 02:16 UTC

Last modified

2026-09-24 17:25 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-835

Record status

Analyzed

Affected

• Openstack Swift < 2.35.3
• Openstack Swift < 2.36.2
• Openstack Swift < 2.37.2

Attack profile CVSS 4.0 · 7.1

Attack vector

Network

Complexity

Low

Attack requirements

None

Privileges needed

Low

User interaction

None

Confidentiality

None

Integrity

None

Availability

High