D-Link DIR-823X Command Injection
CVE-2025-29635 is a high-severity improper neutralization of special elements used in a command vulnerability in Dir-823x Firmware from D-Link, 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 Dir-823x Firmware versions: 240126; 240802. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on April 24, 2026, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Check which version of Dir-823x Firmware you run against the affected versions below, and install the vendor's latest release.
- CISA's required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| D-Link | Dir-823x Firmware | 240126; 240802 | Not stated |
Version data comes from NVD's product matching. 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 CISA (ADP).
Official description
A command injection vulnerability in D-Link DIR-823X 240126 and 240802 allows an authorized attacker to execute arbitrary commands on remote devices by sending a POST request to /goform/set_prohibiting via the corresponding function, triggering remote command execution.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements used in a Command
The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.
How developers prevent this class of flaw
- If at all possible, use library calls rather than external processes to recreate the desired functionality.
- If possible, ensure that all external commands called from the program are statically created.
- Run time: Run time policy enforcement may be used in an allowlist fashion to prevent use of any non-sanctioned commands.
More Improper Neutralization of Special Elements used in a Command vulnerabilities (CWE-77)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-29635US Government Resource
Technical write-ups (may include proof of concept)
- akamai.com/blog/security-research/2026/apr/cve-2025-29635-mirai-campaign-targets-d-link-devicesExploit, Third Party Advisory
Other vulnerabilities in Dir-823x Firmware
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
Recent Improper Neutralization of Special Elements used in a Command vulnerabilities
- 8.6 High severity
- 8.8 High severity
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
Spotted an error? Tell us.