A new Mirai-based malware campaign is actively exploiting CVE-2025-29635, a high-severity command-injection vulnerability affecting D-Link DIR-823X routers, to enlist devices into the botnet. CVE-2025-29635 allows an attacker to execute arbitrary commands on remote devices by sending a POST request to a vulnerable endpoint, triggering remote command execution (RCE). Akamai's SIRT, which detected the Mirai campaign in March 2026, reports that, although the flaw was first disclosed 13 months ago by security researchers Wang Jinshuai and Zhao Jiangting, this is the first time in-the-wild active exploitation has been observed. "The Akamai SIRT discovered active exploitation attempts of the D-Link command injection vulnerability CVE-2025-29635 in our global network of honeypots in early March 2026," reads Akamai's report. "This vulnerability exists in D-Link DIR-823X series routers in firmware versions 240126 and 24082, and allows an authorized attacker to execute arbitrary commands on remote devices by sending a POST request to the /goform/set_prohibiting endpoint via the corresponding function, which can trigger remote command execution." The researchers who discovered the flaw briefly published a proof-of-concept (PoC) exploit on GitHub, but later retracted it. Akamai's observations show attackers are sending POST requests that change directories across writable paths, download a shell script (dlink.sh) from an external IP, and execute it. The script installs a Mirai-based malware named "tuxnokill," which supports multiple architectures.