WL-NU516U1: Improper Neutralization of Special Elements in Output Used by a Downstream Component
CVE-2026-2615 is a high-severity improper neutralization of special elements in output used by a downstream component vulnerability in WL-NU516U1 from WAVLINK, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected WL-NU516U1 versions: 20251208. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 13.2% chance of exploitation within 30 days, which is in the top 3.56% of all scored CVEs.
EPSS places it among the vulnerabilities most likely to be exploited soon.
What to do
- Check which version of WL-NU516U1 you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| WAVLINK | WL-NU516U1 | 20251208 | Not stated |
| WAVLINK | Wl-nu516u1 Firmware | 2025-12-08 and earlier | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (vuldb.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.3 | High | CNA (vuldb.com) |
| CVSS 3.1 | 7.2 | High | CNA (vuldb.com) |
| CVSS 2.0 | 8.3 | High | CNA (vuldb.com) |
Official description
A flaw has been found in Wavlink WL-NU516U1 up to 20251208. The affected element is the function singlePortForwardDelete of the file /cgi-bin/firewall.cgi. Executing a manipulation of the argument del_flag can lead to command injection. The attack may be launched remotely. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements in Output Used by a Downstream Component
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
How developers prevent this class of flaw
- Programming languages and supporting technologies might be chosen which are not subject to these issues.
- Utilize an appropriate mix of allowlist and denylist parsing to filter control-plane syntax from all input.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- vuldb.com/?id.346265Third Party Advisory, VDB Entry
- vuldb.com/?submit.751047Third Party Advisory, VDB Entry
Technical write-ups (may include proof of concept)
Other references
- vuldb.com/?ctiid.346265Permissions Required, VDB Entry
Other vulnerabilities in WL-NU516U1
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 8.8 High severity
- 7.2 High severity
- 7.2 High severity
Recent Improper Neutralization of Special Elements in Output Used by a Downstream Component vulnerabilities
- 7.3 High severity
- 7.3 High severity
- 7.3 High severity
- 7.6 High severity
- 9.8 Critical severity
- 9.8 Critical severity
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