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TI-2026-23700 Aliases CVE-2026-30871

OpenWrt Project has Stack-based Buffer Overflow in DNS PTR Query

Priority MEDIUM 51CWE-121Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Attack requirements
None
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-121 and the CVSS impact.

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 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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01286 70th percentileScored 2026-11-07
Fix Fixed openwrt (openwrt): 24.10.6, 25.12.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
openwrtopenwrtbefore 24.10.6; 25.12.0-rc1 to before 25.12.124.10.6, 25.12.1Patch availableCNA
  • openwrt Vendoropenwrt Affected before 24.10.6; 25.12.0-rc1 to before 25.12.1 Fixed in 24.10.6, 25.12.1 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:o:openwrt:openwrt:*:*:*:*:*:*:*:*before 24.10.6; 25.12.0 to before 25.12.1Vulnerableopenwrt
  • cpe:2.3:o:openwrt:openwrt:*:*:*:*:*:*:*:* Versions before 24.10.6; 25.12.0 to before 25.12.1 Vulnerable ·openwrt

Remediation

  • Fix · CNA openwrt (openwrt) Fixed in 24.10.6, 25.12.1

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-30871
  2. 2026-11-03 CISA SSVC decision points changed

References

Advisory 1

Other 2

  • TI-2024-13053 Improper input validation in MediaTek MT6890, MT7915, MT7916, MT7981, MT7986 CVSS 3.1CRITICAL 9.8
  • TI-2026-44983 Cross-site scripting in openwrt CVSS 3.1CRITICAL 9.6
  • TI-2026-40045 OpenWrt: EAD Integer Underflow → Pre-Auth Denial of Service CVSS 3.1MEDIUM 6.5
  • TI-2023-09914 LuCI openwrt-22.03 branch git-22.361.69894-438c598 was discovered to contain a stored… CVSS 3.1MEDIUM 5.4
  • TI-2026-44982 OpenWrt: ACL bypass and arbitrary root file read via cgi-io cgi-download CVSS 3.1MEDIUM 4.9
  • TI-2026-23701 OpenWrt Project has a Stack-based Buffer Overflow vulnerability via IPv6 reverse DNS lookup CVSS 4.0CRITICAL 9.5
See all 136 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences