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Vulnerabilities

Vulnerability · CVE-2026-30871

OpenWrt Project is a Linux operating system targeting embedded devices.

Published Mar 19, 2026 · catalog updated Jun 17, 2026 · OpenWrt Project is a

Check if you run it

No confirmed exploitation is on record for CVE-2026-30871. EPSS is 0.70%. Act only if a listed version of OpenWrt Project is a is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (OpenWrt Project is a).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Critical9.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.70%
Remediation
Advisory link
Affected products
cpe openwrt/openwrt

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe openwrt/openwrtversion unspecified

How to fix CVE-2026-30871

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-30871. EPSS is 0.70%. Act only if a listed version of OpenWrt Project is a is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-121: Stack-based Buffer Overflow. EPSS 0.70%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Mar 19, 2026 · NIST NVD

    Detected

    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 (

  2. Jun 17, 2026 · NIST NVD

    Updated

    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 (

Sources

  • CVE.orgVulnerability recordCVE-2026-30871

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-30871

    30-day exploitation probability 0.7%

    first.org
  • NIST NVDVulnerability recordCVE-2026-30871

    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-ad

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.