{"id":"CVE-2026-26310","aliases":["BIT-envoy-2026-26310","GHSA-3cw6-2j68-868p"],"url":"https://o3.security/vulnerability/CVE-2026-26310","summary":"Crash for scoped ip address in Envoy during DNS","details":"### Summary\n\nCalling `Utility::getAddressWithPort` with a scoped IPv6 addresses causes a crash. This utility is called in the data plane from the original_src filter and the dns filter.\n\n### Details\n\nThe crashing function is `Utility::getAddressWithPort`. The crash occurs if a string containing a scoped IPv6 address is passed to this function.\n\nThis vulnerability affects:\n\n1. The **original src filter**: If the filter is configured and the original source is a scoped IPv6 address, it will cause a crash.\n2. **DNS response address resolution**: If a DNS response contains a scoped IPv6 address, this will also trigger the crash.\n\n### PoC\n\nTo reproduce the vulnerability:\n\n1. **Method A (Original Src Filter):** Configure the `original src` filter in Envoy and provide a scoped IPv6 address as the original source.\n2. **Method B (DNS Resolution):** Trigger a DNS resolution process within Envoy where the DNS response contains a scoped IPv6 address.\n\n### Impact\n\nThis is a Denial of Service (DoS) vulnerability. It impacts users who have the `original src` filter configured or whose Envoy instances resolve addresses from DNS responses that may contain scoped IPv6 addresses.","published":"2026-03-10T19:08:22.330Z","modified":"2026-08-12T03:51:25.732041842Z","cvss":{"score":5.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/envoyproxy/envoy","fixedVersion":null},{"ecosystem":"Go","name":"github.com/envoyproxy/envoy","fixedVersion":null},{"ecosystem":"Go","name":"github.com/envoyproxy/envoy","fixedVersion":null},{"ecosystem":"Go","name":"github.com/envoyproxy/envoy","fixedVersion":null}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/26xxx/CVE-2026-26310.json"},{"type":"ADVISORY","url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-3cw6-2j68-868p"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-26310"},{"type":"PACKAGE","url":"https://github.com/envoyproxy/envoy"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:25.732041842Z"}}