CVE-2026-80349CWE-290

CVE-2026-80349

Critical · published August 26, 2026

CVSS v3.1
9.8
EPSS
1%
Percentile
46.8
In the wild
Unconfirmed
What it is

TarsWeb decides whether a request comes from a trusted local caller using a client-controlled header. app.js sets Koa's proxy option to true without naming which upstream proxies may be trusted and without limiting the number of forwarded hops, so the request address Koa reports is taken from the X-Forwarded-For header supplied by the caller. In midware/ssoMidware.js a single branch covers both the ignored-path list and the ignoreIps allowlist from config/loginConf.js, which contains the loopback address, and that branch assigns the effective account identity from the uid query parameter before falling through to the request without validating any ticket, cookie or password. A request carrying a forged X-Forwarded-For value naming the loopback address and a uid naming an existing account therefore reaches every route the console mounts as that account, including an administrator, with no credential of any kind. Those routes include user and role administration, service configuration, and package upload and deployment. Version 3.0.16 separates the two branches so that a match on the address allowlist assigns the configured default account rather than one named by the caller.

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
9.3 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
EPSS
0.00575 · 46.8th percentile
Weakness
CWE-290 · Authentication Bypass by Spoofing
Published
2026-08-26T14:16Z
References (6)
EPSS history
Timeline
  • 28 AUG 06:54Z
    EPSS moved — → 0%
    epss
  • 26 AUG 10:09Z
    TarsWeb through 3.0.14 Authentication Bypass via Spoofed X-Forwarded-For and uid Parameter
    cvelistv5