CVE-2026-49352: 9router's Hardcoded Default fallback JWT Secret Allows Authentication Bypass

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
• EPSS 0.6%, percentile 48: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 48% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes 9router (npm) >= 0.2.21, <= 0.4.41, fixed in 0.4.45. Check your lockfile, including transitive dependencies.

What it is

9Router is an AI router & token saver. From 0.2.21 until 0.4.44, 9Router used the hardcoded fallback JWT secret 9router-default-secret-change-me in src/app/api/auth/login/route.js, src/middleware.js, and later src/lib/auth/dashboardSession.js, allowing attackers to forge an authtoken cookie when JWTSECRET was unset. This issue is fixed in version 0.4.44

From the GitHub advisory

Summary 9router uses a publicly known hardcoded string "9router-default-secret-change-me" as the fallback of JWT secret for all Dashboard session JWTs when the JWTSECRET environment variable is not set. Because this secret is committed in the public repository and unchanged across all releases, any unauthenticated remote attacker can forge a valid authtoken cookie and gain full access to dashboard and api (If JWTSECRET is not set on server) . This vulnerable affected so many public 9router server Details | Versions | File | Note | |---|---|---| | >= 0.2.21, = 0.4.31,

Vulnerable Code

v0.2.21 – v0.4.30 — src/app/api/auth/login/route.js and src/middleware.js:

v0.4.31 – v0.4.41 (current) — src/lib/auth/dashboardSession.js (centralized via OIDC refactor, commit c3d91b0):

The fallback string was introduced in commit 23cfb19 (2026-01-09) and has never been removed. The OIDC refactor in c3d91b0 only relocated it to a shared module . This vulnerability has existed since 9router first introduced authentication. PoC Step 1. Craft a JWT signed with the known default secret:

Weakness type: CWE-798.

Product: 9router (npm) · Assigned by: GitHub_M · Published: 2026-07-15

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: none (no login)
• User interaction: none
• Scope: unchanged

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation poc, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.60% probability of exploitation activity in the next 30 days; percentile 48.

Timeline

• 2026-07-02 — GitHub-reviewed advisory GHSA-jphh-m39h-6gwx published (critical)
• 2026-07-15 — CVE record published by GitHub_M
• 2026-07-16 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-jphh-m39h-6gwx github.com
2. CVE.org record CVE-2026-49352 cve.org
3. NVD entry CVE-2026-49352 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com

Critical npm advisories · Today’s Security Digest