CVE-2026-49017
OpenStack Swift: s3api middleware enters an infinite loop when processing a truncated aws-chunked PUT request body
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
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.
- Record
CVE-2026-49017- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L - Weakness
- CWE-835
- Updated
- 2026-11-02
EUVDEUVD-2026-32040
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.
- Record
EUVD-2026-32040- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-g7jq-j257-rww2
OpenStack Swift: s3api middleware enters an infinite loop when processing a truncated aws-chunked PUT request body
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.
- Record
GHSA-g7jq-j257-rww2- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L - Weakness
- CWE-835
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-49017- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-835
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2026-49017- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L - Weakness
- CWE-835
- Updated
- 2026-11-02
OSVDEBIAN-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.
- Record
DEBIAN-CVE-2026-49017- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Show 4 moreShow less
OSVGHSA-g7jq-j257-rww2
OpenStack Swift: s3api middleware enters an infinite loop when processing a truncated aws-chunked PUT request body
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.
- Record
GHSA-g7jq-j257-rww2- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L - Weakness
- CWE-835
- Updated
- 2026-11-02
OSVPYSEC-2026-3080
OpenStack Swift: s3api middleware enters an infinite loop when processing a truncated aws-chunked PUT request body
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.
- Record
PYSEC-2026-3080- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L - Updated
- 2026-11-02
OSVUBUNTU-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.
- Record
UBUNTU-CVE-2026-49017- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUSN-8821-1 No score
swift vulnerability
It was discovered that OpenStack Swift incorrectly handled truncated aws-chunked PUT request bodies in its s3api middleware. An authenticated attacker could possibly use this issue to cause OpenStack Swift to use excessive resources, leading to a denial of service.
- Record
USN-8821-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
swiftPyPI |
2.36.0 to 2.36.1 | None known |
swiftPyPI |
2.37.0 to 2.37.1 | None known |
swiftDebian:13 |
before 2.35.1-0+deb13u2, plus listed versions 2.35.0-42.35.1-0+deb13u1 |
2.35.1-0+deb13u2 |
swiftDebian:14 |
before 2.37.1-4, plus listed versions 2.35.0-42.35.1-12.35.1-22.36.0-12.36.0-2 Show 10 moreShow less2.36.0-32.36.0-42.36.0-52.36.0-62.36.0-72.36.0-82.37.0-12.37.1-12.37.1-22.37.1-3 |
2.37.1-4 |
swiftPyPI |
2.36.0 to 2.36.1, 2.37.0 to 2.37.1 | None known |
swiftUbuntu:25.10 |
All versions, plus listed versions 2.35.0-0ubuntu12.35.0+git2025070714.1428eb3b5-0ubuntu12.36.0-0ubuntu12.36.0-0ubuntu1.1 |
None known |
swiftUbuntu:26.04:LTS |
before 2.37.1-0ubuntu2.1, plus listed versions 2.36.0-0ubuntu12.37.0-0ubuntu12.37.1-0ubuntu2 |
2.37.1-0ubuntu2.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-49017 is a high vulnerability (CVSS 7.1) in Openstack Swift, published May 27, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.36%, the 29th percentile. Fixed in swift 2.35.1-0+deb13u2.
References
bugs.launchpad.net/bugs/2152205
review.opendev.org/c/openstack/swift/+/987957
openwall.com/lists/oss-security/2026/05/27/9
nvd.nist.gov/vuln/detail/CVE-2026-49017
Show 9 moreShow less
github.com/advisories/GHSA-g7jq-j257-rww2
opendev.org/openstack/swift
security-tracker.debian.org/tracker/CVE-2026-49017
pypi.org/project/swift
ubuntu.com/security/CVE-2026-49017
cve.org/CVERecord?id=CVE-2026-49017