Regular expression denial of service in OpenStack Swift
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 4 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-1333.
Summary
In OpenStack Swift through 2.38.0, the proxy server Accept header parser contains a regular expression vulnerable to catastrophic backtracking (ReDoS). The "qdtext" pattern (?:[^"]|\\.)* allows an unauthenticated remote attacker to send a crafted Accept header that causes exponential CPU consumption in the proxy worker. A payload of 32 backslash-character pairs exceeds 30 seconds of CPU time. No authentication is required. Repeated requests can exhaust all proxy worker threads, resulting in a complete denial of service.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| OpenStack | Swift | 1.9.1 to before 2.35.4; 2.36.0 to before 2.36.3; 2.37.0 to before 2.37.3; 2.38.0 | 2.35.4, 2.36.3, 2.37.3 | Patch available | CNA |
- Swift VendorOpenStack Affected 1.9.1 to before 2.35.4; 2.36.0 to before 2.36.3; 2.37.0 to before 2.37.3; 2.38.0 Fixed in 2.35.4, 2.36.3, 2.37.3 Patch available CNA
Remediation
- Fix · CNA Swift (OpenStack) Fixed in 2.35.4, 2.36.3, 2.37.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat OpenStack Platform 13 (Queens) | Affected | No fix planned: Will not fix |
| Red Hat OpenStack Platform 16.2 | Affected | No fix yet |
| Red Hat OpenStack Platform 17.1 | Affected | No fix yet |
| Red Hat OpenStack Platform 18.0 | Affected | No fix yet |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-71190
- 2026-10-03 Alias added: GHSA-4jj7-q8c5-78g4
References
More OpenStack vulnerabilities
- TI-2026-78562 Incorrect authorization in OpenStack Manila share operations CVSS 3.1CRITICAL 9.9
- TI-2026-63467 Code injection in OpenStack Octavia CVSS 4.0CRITICAL 9.4
- TI-2017-13226 The tcpmss_mangle_packet function in net/netfilter/xt_TCPMSS.c in the Linux kernel before… CVSS 3.1CRITICAL 9.8
- TI-2026-69629 OpenStack Mistral flaw lets users change other projects' resources CVSS 4.0HIGH 7.2
- TI-2026-69623 Command injection in OpenStack Mistral std.ssh_proxied action CVSS 4.0HIGH 8.7
- TI-2022-17779 Improper privilege management in OpenStack CVSS 3.1HIGH 8.8
Sources
- CVE-2026-71190 · CVE Program
- CVE-2026-71190 · NVD
- FIRST EPSS
- GHSA-4jj7-q8c5-78g4 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-71190 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences