CVE-2026-26310

Impact

### Summary Calling `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. ### Details The crashing function is `Utility::getAddressWithPort`. The crash occurs if a string containing a scoped IPv6 address is passed to this function. This vulnerability affects: 1. The **original src filter**: If the filter is configured and the original source is a scoped IPv6 address, it will cause a crash. 2. **DNS response address resolution**: If a DNS response contains a scoped IPv6 address, this will also trigger the crash. ### PoC To reproduce the vulnerability: 1. **Method A (Original Src Filter):** Configure the `original src` filter in Envoy and provide a scoped IPv6 address as the original source. 2. **Method B (DNS Resolution):** Trigger a DNS resolution process within Envoy where the DNS response contains a scoped IPv6 address. ### Impact This 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.

Affected packages

Affected products

Weakness classification

References

• NVD record
• CVE.org record
• GitHub advisory
• https://github.com/envoyproxy/envoy/security/advisories/GHSA-3cw6-2j68-868p
• https://github.com/advisories/GHSA-3cw6-2j68-868p
• https://nvd.nist.gov/vuln/detail/CVE-2026-26310