What’s Vulnerable › Vulnerabilities

CVE-2026-49017

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-27 · updated 2026-09-24
• Weakness: CWE-835

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.

Affected products

• OpenStack Swift: from 2.35.1 before 2.35.3; from 2.36.0 before 2.36.2; from 2.37.0 before 2.37.2 — fixed in 2.35.3, 2.36.2, 2.37.2

How to fix

Upgrade to a fixed version: OpenStack Swift 2.35.3, 2.36.2, 2.37.2. Check the vendor advisory for mitigations.

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

Get alerted when CVE-2026-49017 or the next vulnerability affects your stack