CVSS 3.0
7.6 highCVSS:3.0/AV:N/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:HCVE-2026-107243
High (7.6) in versa vos. EPSS 0.3% estimated probability of exploitation activity in the next 30 days.
On this page
The Node.js web service on VOS (previously Versa FlexVNF) is used for URL-based Zero Touch Provisioning (ZTP) of the VOS appliance and is not required after provisioning is complete. The express-session middleware in server.js is configured with a hardcoded secret that is identical across all VOS appliances and is used to sign session cookies. An attacker who obtains a valid session ID from any source can compute the correct HMAC-SHA256 signature and forge a session cookie that the server accepts as legitimate. Because the secret is shared across all VOS appliances, a forged cookie is accepted by any VOS appliance in the deployment.
Versa’s security hardening guide for Hubs, Branches, and Controllers recommends disabling the Node.js web service after the initial provisioning of the VOS device. This vulnerability is not exploitable on VOS devices where the Node.js web service has been disabled.
Severity
- EPSS
- 0.3% estimated probability of exploitation activity in the next 30 days; 22nd percentile. Scored 2026-11-10. A forecast for this CVE across the internet, not for your own systems.
- CWE
- CWE-798 Use of Hard-coded Credentials
- OWASP Top 10
- A07:2025 Authentication Failures
- Published
- Assigned by
- hackerone (CNA)
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
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Explain CVE-2026-107243 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-107243?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-107243?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-107243 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| Versa VOS | from 21.1.1 through 21.2.3 |
| Versa VOS | from 22.1.2 before July 2, 2026 |
| Versa VOS | from 22.1.3 before July 2, 2026 |
| Versa VOS | from 22.1.4 before July 2, 2026 |
| Versa VOS | from 23.1.2 before Aug 3, 2026 |
Fixed in
| Product | Fixed in |
|---|---|
| Versa VOS | 22.1.2 July-2-2026-Hotfix |
| Versa VOS | 22.1.3 July-2-2026-Hotfix |
| Versa VOS | 22.1.4 July-2-2026-Hotfix |
| Versa VOS | 23.1.2 Aug-3-2026-Hotfix |
Attack patterns (CAPEC)
- CAPEC-70 Try Common or Default Usernames and Passwords Likelihood: Medium · Severity: High
- CAPEC-191 Read Sensitive Constants Within an Executable Severity: Low
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.