Traefik is an open source HTTP reverse proxy and load balancer. From 3.6.11 until 3.6.25 and 3.7.10, Traefik's BasicAuth middleware in pkg/middlewares/auth/basic_auth.go deduplicates concurrent password checks with a singleflight key built from the delimiter-free concatenation of password and secret, allowing an attacker who has a valid credential and the stored hash to authenticate as an unconfigured username when headerField trusts the forwarded identity. This issue is fixed in 3.6.25 and 3.7.10.
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-287"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/71xxx/CVE-2026-71326.json"
}{
"cpe": "cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*",
"extracted_events": [
{
"introduced": "3.6.11"
},
{
"fixed": "3.6.25"
},
{
"introduced": "3.7.0"
},
{
"fixed": "3.7.10"
}
],
"source": [
"CPE_RANGE",
"REFERENCES"
]
}