CVE-2026-30872 OpenWrt Project has a Stack-based Buffer Overflow vulnerability via IPv6 reverse DNS lookup
A stack-based buffer overflow in the mdns daemon allows remote code execution via crafted IPv6 reverse DNS queries.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-30872?
CVE-2026-30872 is a critical memory corruption vulnerability in Openwrt Openwrt, published on 19 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
OpenWrt Project is a Linux operating system targeting embedded devices. In versions prior to 24.10.6 and 25.12.1, the mdns daemon has a Stack-based Buffer Overflow vulnerability in the match_ipv6_addresses function, triggered when processing PTR queries for IPv6 reverse DNS domains (.ip6.arpa) received via multicast DNS on UDP port 5353. During processing, the domain name from name_buffer is copied via strcpy into a fixed 256-byte stack buffer, and then the reverse IPv6 request is extracted into a buffer of only 46 bytes (INET6_ADDRSTRLEN). Because the length of the data is never validated before this extraction, an attacker can supply input larger than 46 bytes, causing an out-of-bounds write. This allows a specially crafted DNS query to overflow the stack buffer in match_ipv6_addresses, potentially enabling remote code execution. This issue has been fixed in versions 24.10.6 and 25.12.1.
Weakness: CWE-121
Which versions are affected by CVE-2026-30872?
It affects 1 product.
Products include Openwrt Openwrt.
How do I fix CVE-2026-30872?
No fix has been published for CVE-2026-30872 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-30872 being exploited?
There is no known exploitation of CVE-2026-30872 in the wild and no public exploit code.
Other vulnerabilities in Openwrt Openwrt
Sources
Also known as GHSA-mpgh-v658-jqv5.