# CVE-2026-13763: AWS Application Load Balancer WAF bypass via HTTP/2 multi-frame requests

Source: https://junglewise.ai/threats/cve-2026-13763-aws-application-load-balancer-waf-bypass-via-http-2-multi-frame  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-29. Updated: 2026-06-29  
License: CC BY 4.0 with a link back

CVE-2026-13763 · Severity: critical · CVSS 9.8 · Published 2026-06-29

AWS Application Load Balancer (ALB) has a vulnerability where it may fail to properly inspect the full content of certain web requests when AWS WAF is enabled. An attacker could bypass security rules by splitting a malicious request into multiple parts, potentially allowing unauthorized or harmful traffic to reach your backend servers. This issue specifically affects load balancers configured to use HTTP/2 for their target groups.

Vendors: [AWS](https://junglewise.ai/threats/vendors/aws).

## Quick answers

**Is CVE-2026-13763 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-13763 being exploited in the wild.

**How severe is CVE-2026-13763?** Critical severity, with a CVSS score of 9.8, published 29 June 2026.

**Which products and versions are affected?** AWS Application Load Balancer All versions using HTTP/2 target groups.

**Is there a fix for CVE-2026-13763?** A patch was published on 2026-05-22: Remediation configuration option released by AWS Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-13763 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-13763?** Check whether you run AWS Application Load Balancer 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 vulnerability classified as CWE-444 (Inconsistent Interpretation of HTTP Requests) exists in AWS Application Load Balancer when integrated with AWS WAF. The flaw stems from how the ALB handles HTTP/2 multi-frame request bodies; an attacker can fragment a request body across multiple frames such that the WAF only inspects a partial body, effectively bypassing security rules. This issue specifically impacts ALB target groups configured for HTTP/2. AWS has released a remediation via a new target group attribute, 'Inspect after sufficient data', which forces the ALB to accumulate data frames before performing WAF inspection.

## Affected products

- AWS Application Load Balancer (ALB) All versions using HTTP/2 target groups

## Timeline

- 2026-05-22: patched: Remediation configuration option released by AWS
- 2026-06-29: disclosed: Public advisory and CVE published

## References

- [https://aws.amazon.com/security/security-bulletins/2026-048-aws/](https://aws.amazon.com/security/security-bulletins/2026-048-aws/)
- [https://docs.aws.amazon.com/elasticloadbalancing/latest/application/edit-target-group-attributes.html](https://docs.aws.amazon.com/elasticloadbalancing/latest/application/edit-target-group-attributes.html)