CVE-2026-13763 PUBLISHED

HTTP/2 Stream Parser Confusion Body-Inspection Bypass in AWS Application Load Balancer with AWS WAF

Assigner: AMZN
Reserved: 29.06.2026 Published: 29.06.2026 Updated: 29.06.2026

Inconsistent interpretation of HTTP/2 requests in AWS Application Load Balancer with AWS WAF enabled might allow remote actors to bypass AWS WAF managed rule body inspection via crafted HTTP/2 requests that fragment the request body across frames so that only a partial body is inspected. This issue only impacts HTTP/2 ALB target groups.

To remediate this issue, customers should enable the "Inspect after sufficient data" target group configuration associated to an ALB load balancer. Refer to: ( https://docs.aws.amazon.com/elasticloadbalancing/latest/application/edit-target-group-attributes.html#waf-http2-inspection )

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H
CVSS Score: 7.9

Product Status

Vendor AWS
Product AWS Application Load Balancer
Versions Default: unaffected
  • Version 0 is affected

References

Problem Types

  • CWE-444 Inconsistent interpretation of HTTP requests ('HTTP Request/Response smuggling') CWE

Impacts

  • CAPEC-278 Web Services Protocol Manipulation