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CVE-2026-30871
CRITICAL · CVSS 9.8
EPSS exploitation probability: 0%
Published 2026-03-19T22:16:31.633 · Last modified 2026-06-17T10:33:03.913

Summary

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 parse_question function. The issue is triggered by PTR queries for reverse DNS domains (.in-addr.arpa and .ip6.arpa). DNS packets received on UDP port 5353 are expanded by dn_expand into an 8096-byte global buffer (name_buffer), which is then copied via an unbounded strcpy into a fixed 256-byte stack buffer when handling TYPE_PTR queries. The overflow is possible because dn_expand converts non-printable ASCII bytes (e.g., 0x01) into multi-character octal representations (e.g., \001), significantly inflating the expanded name beyond the stack buffer's capacity. A crafted DNS packet can exploit this expansion

Affected products

openwrt — openwrt

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.