CVE-2026-80349
Authentication bypass
- Published26 Aug 2026
Description
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.
CVSS 3.1 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HRemediation
No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.
References
- https://github.com/TarsCloud/TarsWeb
- https://github.com/TarsCloud/TarsWeb/blob/v3.0.14/app.js
- https://github.com/TarsCloud/TarsWeb/blob/v3.0.14/midware/ssoMidware.js
- https://github.com/TarsCloud/TarsWeb/issues/212
- https://www.vulncheck.com/advisories/tarsweb-through-3.0.14-authentication-bypass-via-spoofed-x-forwarded-for-and-uid-parameter
Related CVEs
Recent high-severity vulnerabilities sharing a weakness type.
Frequently asked
Is CVE-2026-80349 being actively exploited?
CVE-2026-80349 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.57%.
How severe is CVE-2026-80349?
CVE-2026-80349 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.57% probability of exploitation.
How do I fix CVE-2026-80349?
Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2026-80349 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.