CVE-2026-30872

Published Mar 19, 2026

Last updated a month ago

CVSS critical 9.5

Overview

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.
Source
security-advisories@github.com
NVD status
Analyzed
Products
openwrt

Risk scores

CVSS 4.0

Type
Secondary
Base score
9.5
Impact score
-
Exploitability score
-
Vector string
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Severity
CRITICAL

CVSS 3.1

Type
Primary
Base score
9.8
Impact score
5.9
Exploitability score
3.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity
CRITICAL

Weaknesses

security-advisories@github.com
CWE-121

Social media

Hype score
Not currently trending

Configurations

Related CVEs

  1. LuCI is the OpenWrt Configuration Interface. Versions prior to both 24.10.5 and 25.12.0, contain a stored XSS vulnerability in the wireless scan modal, where SSID values from scan results are rendered as raw HTML without any sanitization. The wireless.js file in the luci-mod-network package passes SSIDs via a template literal to dom.append(), which processes them through innerHTML, allowing an attacker to craft a malicious SSID containing arbitrary HTML/JavaScript. Exploitation requires the user to actively open the wireless scan modal (e.g., to connect to a Wi-Fi access point or survey nearby channels), and only affects OpenWrt versions newer than 23.05/22.03 up to the patched releases (24.10.6 and 25.12.1). The issue has been fixed in version LuCI 26.072.65753~068150b.•CVE-2026-32721
  2. OpenWrt Project is a Linux operating system targeting embedded devices. In versions prior to 24.10.6, a vulnerability in the hotplug_call function allows an attacker to bypass environment variable filtering and inject an arbitrary PATH variable, potentially leading to privilege escalation. The function is intended to filter out sensitive environment variables like PATH when executing hotplug scripts in /etc/hotplug.d, but a bug using strcmp instead of strncmp causes the filter to compare the full environment string (e.g., PATH=/some/value) against the literal "PATH", so the match always fails. As a result, the PATH variable is never excluded, enabling an attacker to control which binaries are executed by procd-invoked scripts running with elevated privileges. This issue has been fixed in version 24.10.6.•CVE-2026-30874
  3. OpenWrt Project is a Linux operating system targeting embedded devices. In versions prior to both 24.10.6 and 25.12.1, the jp_get_token function, which performs lexical analysis by breaking input expressions into tokens, contains a memory leak vulnerability when extracting string literals, field labels, and regular expressions using dynamic memory allocation. These extracted results are stored in a jp_opcode struct, which is later copied to a newly allocated jp_opcode object via jp_alloc_op. During this transfer, if a string was previously extracted and stored in the initial jp_opcode, it is copied to the new allocation but the original memory is never freed, resulting in a memory leak. This issue has been fixed in versions 24.10.6 and 25.12.1.•CVE-2026-30873
  4. 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 behavior to overflow the stack buffer, making the vulnerability reachable through normal multicast DNS packet processing. This issue has been fixed in versions 24.10.6 and 25.12.1.•CVE-2026-30871
  5. In preloader, there is a possible read of device unique identifiers due to a logic error. This could lead to local information disclosure, if an attacker has physical access to the device, with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS10607099; Issue ID: MSV-6118.•CVE-2026-20435

References

Sources include official advisories and independent security research.