CVE-2026-49017
CVE-2026-49017 is a high-severity vulnerability with a CVSS 4.0 base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-835.
Key facts
- Severity: High (CVSS 4.0 base score 7.1)
- EPSS exploit prediction: 0% (24th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-32040
- Weakness: CWE-835
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-49017?
- 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.
- How severe is CVE-2026-49017?
- CVE-2026-49017 has a CVSS 4.0 base score of 7.1, rated high severity.
- Is CVE-2026-49017 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-49017?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-49017 have an EU (EUVD) identifier?
- Yes. CVE-2026-49017 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32040.
- When was CVE-2026-49017 published?
- CVE-2026-49017 was published on 2026-05-27 and last updated on 2026-06-17.
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
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