CVE-2026-47774
7.5 ÉlevéeDescription
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.35.11, 1.36.7, 1.37.3, and 1.38.1, a vulnerability in Envoy's HTTP/2 downstream request processing allows an unauthenticated remote client to trigger excessive memory consumption, potentially resulting in OOM termination of the Envoy process and denial of service. The issue arises from the combination of two behaviors. First, cookie header bytes are not fully accounted for during request header size validation in Envoy. Second, HPACK header block limits in oghttp2/quiche are enforced on encoded bytes without a corresponding limit on total decoded header size. Together, these behaviors allow a malicious client to cause large decoded header allocations while bypassing the intended request header size protections. Versions 1.35.11, 1.36.7, 1.37.3, and 1.38.1 contain a fix. No complete workaround is known short of applying a fix. Possible temporary mitigations include disabling downstream HTTP/2 where operationally feasible; enforcing stricter request header and cookie limits before traffic reaches Envoy; and monitoring Envoy memory usage for abnormal growth under HTTP/2 traffic.
Produits concernés
Scores CVSS
| Version | Score | Source | Vecteur |
|---|---|---|---|
| 3.1 | 7.5 Élevée | security-advisories@github.com | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | 7.5 Élevée | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Faiblesses (CWE)
Références
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-22m2-hvr2-xqc8 MitigationVendor Advisory
- http://www.openwall.com/lists/oss-security/2026/06/04/15 Mailing ListMitigationThird Party Advisory
- https://access.redhat.com/errata/RHSA-2026:26210 Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:26222 Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:26231 Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:26247 Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:27114 Third Party Advisory
- https://access.redhat.com/security/cve/CVE-2026-47774 Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2487465 ExploitIssue TrackingThird Party Advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-47774.json Third Party Advisory