CVE-2026-15479 Overview
CVE-2026-15479 is a weak password recovery vulnerability [CWE-640] affecting the H3C NX15 router running firmware version V100R017. The flaw resides in the change_passwd function within the /api/login/modify endpoint, which handles administrator password modification. An attacker can manipulate the newPass argument to change the administrator password without proper authentication controls. The attack can be launched remotely across the network, and a public proof-of-concept has been published on GitHub. The vendor was contacted about the disclosure prior to publication.
Critical Impact
Remote attackers can modify the administrator password on affected H3C NX15 devices without prior authentication, enabling full device takeover.
Affected Products
- H3C NX15 router firmware version V100R017
- Administrator Password Modification Endpoint (/api/login/modify)
- change_passwd function within the login management component
Discovery Timeline
- 2026-07-12 - CVE-2026-15479 published to the National Vulnerability Database
- 2026-07-14 - Last updated in NVD database
Technical Details for CVE-2026-15479
Vulnerability Analysis
The vulnerability exists in the H3C NX15 web management interface, specifically within the change_passwd handler exposed through the /api/login/modify API route. This endpoint is responsible for processing administrator password change requests. The implementation fails to enforce sufficient authorization or identity verification before accepting a new password value supplied via the newPass parameter.
Because the request is reachable over the network and does not require valid prior credentials or a secure recovery workflow, an unauthenticated attacker can submit a crafted request to reset the administrator credential. Once the password is overwritten, the attacker gains administrative access to the router. The weakness is categorized under [CWE-640] Weak Password Recovery Mechanism for Forgotten Password.
A public proof-of-concept has been published in a GitHub repository, increasing the likelihood of opportunistic exploitation against internet-exposed devices.
Root Cause
The root cause is an insecure password recovery and modification workflow. The change_passwd function trusts the newPass argument supplied in the HTTP request to /api/login/modify without verifying that the requester holds a valid administrative session or possesses proof of ownership such as a current password, secure token, or out-of-band verification. This design defect allows unauthenticated password rewriting.
Attack Vector
Exploitation is performed remotely over the network with low complexity and no user interaction. An attacker sends an HTTP request to the /api/login/modify endpoint containing a chosen value for the newPass argument. If the affected device is reachable, the administrator credential is replaced with the attacker-supplied value. The attacker then authenticates with the new password to gain full administrative control of the router.
See the GitHub PoC Repository and the VulDB CVE Record for technical details.
Detection Methods for CVE-2026-15479
Indicators of Compromise
- HTTP requests targeting the /api/login/modify path containing a newPass parameter, particularly from unexpected source addresses.
- Successful administrator logins to the H3C NX15 web interface immediately following a password modification request.
- Configuration changes, new firewall rules, or DNS setting modifications on the router following unexplained credential changes.
Detection Strategies
- Inspect web server and management interface logs for POST or GET requests to /api/login/modify that were not initiated by known administrators.
- Correlate password change events on network appliances with the source IP addresses that issued them and flag requests originating from the WAN interface.
- Alert on any administrative password change that is not preceded by a valid authenticated session.
Monitoring Recommendations
- Forward router management logs to a centralized logging platform to enable long-term retention and correlation.
- Monitor for unusual outbound traffic from the router itself, which can indicate post-compromise activity.
- Baseline normal administrative activity and generate alerts when password changes occur outside of maintenance windows.
How to Mitigate CVE-2026-15479
Immediate Actions Required
- Restrict access to the H3C NX15 management interface so it is not reachable from the internet or untrusted network segments.
- Place management endpoints behind a VPN or an access control list that only permits trusted administrative hosts.
- Audit the current administrator password and reset it from a trusted host to detect and reverse any unauthorized change.
Patch Information
No vendor patch was referenced in the published CVE data at the time of writing. Consult the VulDB Vulnerability Details and the H3C vendor support channels for updated firmware availability. Apply firmware updates for the NX15 platform as soon as they are released.
Workarounds
- Disable remote WAN-side management on the NX15 device and permit administration only from the internal LAN.
- Segment the router management VLAN and enforce firewall rules that block inbound traffic to the /api/login/modify endpoint from untrusted sources.
- Where feasible, replace or retire affected devices until a vendor-supplied fix is applied.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
