Quick answers
- Is CVE-2026-47207 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-47207 being exploited in the wild.
- How severe is CVE-2026-47207?
- Medium severity, with a CVSS score of 6.5, published 26 June 2026.
- Which products and versions are affected?
- Envoy Proxy Envoy >= 1.34.0, < 1.35.13; >= 1.36.0, < 1.36.9; >= 1.37.0, < 1.37.5; >= 1.38.0, < 1.38.3.
- Is there a fix for CVE-2026-47207?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-47207 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-47207?
- Check whether you run Envoy Proxy Envoy at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A use-after-free vulnerability exists in Envoy's ext_proc filter implementation within the AsyncStreamImpl::onData() function. When an external processing server sends a single gRPC message containing multiple ProcessingResponse messages, the first response may trigger the destruction of the gRPC stream object (callbacks_). If Envoy attempts to process subsequent responses within the same gRPC message, it accesses the now-freed object, leading to a crash. This requires the attacker to control or compromise an ext_proc server. The issue is fixed in versions 1.35.13, 1.36.9, 1.37.5, and 1.38.3.
Affected products
- Envoy Proxy Envoy >= 1.34.0, < 1.35.13; >= 1.36.0, < 1.36.9; >= 1.37.0, < 1.37.5; >= 1.38.0, < 1.38.3
Timeline
- 2026-06-23: advisory: GitHub Security Advisory published
- 2026-06-26: disclosed: CVE published to NVD