CVE-2026-80349
CRITICALCVE-2026-80349 is a critical-severity (CVSS 9.8) CWE-290 vulnerability. O3 Security confirms whether CVE-2026-80349 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
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…
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-80349.
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.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-80349 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-80349 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-80349. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-80349 in your dependencies?
O3 detects CVE-2026-80349 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.