CVE-2026-30872: Openwrt remote code execution (CVSS 9.8)

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.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Openwrt≥ 25.12.0 < 25.12.1 · < 24.10.6

Remediation

Fixed in

Openwrt≥ 25.12.1

Patch & vendor advisories

https://github.com/openwrt/openwrt/security/advisories/GHSA-mpgh-v658-jqv5

References

https://github.com/openwrt/openwrt/releases/tag/v24.10.6Release Notes
https://github.com/openwrt/openwrt/releases/tag/v25.12.1Release Notes
https://github.com/openwrt/openwrt/security/advisories/GHSA-mpgh-v658-jqv5Vendor Advisory

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-30872 being actively exploited?

CVE-2026-30872 is not in the CISA KEV catalog. Its EPSS exploit probability is 1.09%.

How severe is CVE-2026-30872?

CVE-2026-30872 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 1.09% probability of exploitation.

Which products are affected by CVE-2026-30872?

Affected products include Openwrt.

How do I fix CVE-2026-30872?

Upgrade affected software to a fixed version, for example Openwrt 25.12.1 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-30872 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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