CVE-2026-71190 Denial of service in Swift
Unauthenticated attackers can cause denial of service in OpenStack Swift proxy servers via crafted Accept headers triggering catastrophic regex backtracking.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-71190?
CVE-2026-71190 is a high-severity denial of service vulnerability in OpenStack Swift, published on 5 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-1333
Which versions are affected by CVE-2026-71190?
How do I fix CVE-2026-71190?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-71190 being exploited?
There is no known exploitation of CVE-2026-71190 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-71190, GHSA-4jj7-q8c5-78g4, UBUNTU-CVE-2026-71190.