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AWS ALB HTTP/2 Request Body Inspection Bypass in AWS WAF

IdentifiersCVE-2026-13763CWE-444

CVE-2026-13763 is an HTTP/2 request parsing and inspection inconsistency affecting AWS Application Load Balancer (ALB) deployments with AWS WAF enabled. In impacted HTTP/2 ALB target groups, a remote attacker can send crafted multi-frame HTTP/2 requests that fragment the request body across frames in a way that causes AWS WAF managed rule body inspection to evaluate only a partial body. The flaw arises from inconsistent interpretation of HTTP/2 request data between components involved in request handling and WAF inspection, creating a request-inspection bypass condition rather than a memory corruption issue. As a result, malicious payload content placed in uninspected portions of the fragmented body may evade WAF detection and filtering.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can allow an unauthenticated remote attacker to bypass AWS WAF managed rule inspection for HTTP/2 request bodies on affected ALB target groups. This may permit malicious payloads embedded in the uninspected portion of the body to reach backend applications, potentially undermining protections intended to block application-layer attacks. The provided source material states high confidentiality, integrity, and availability impact in the CVSS v3.1 assessment, but the direct, verified impact described in the advisory is WAF inspection bypass leading to exposure of downstream applications to otherwise blocked malicious requests.

Mitigation

If you can’t patch tonight, do this now.

As an immediate mitigation, review AWS WAF deployments behind Application Load Balancer and ensure HTTP/2 inspection behavior is configured so ALB accumulates sufficient HTTP/2 body data before WAF inspection. Apply this setting to all affected HTTP/2 ALB target groups. If operationally feasible, reducing exposure of HTTP/2 endpoints until the configuration is updated may reduce risk, but the specific vendor-recommended mitigation in the provided content is enabling "Inspect after sufficient data."

Remediation

Patch, then assume compromise.

Enable the ALB target group configuration "Inspect after sufficient data" for affected HTTP/2 ALB target groups so that HTTP/2 data frames are accumulated before AWS WAF inspection and the full relevant request body is inspected. AWS indicates this configuration is the customer remediation for ALB deployments. Review all ALB target groups handling HTTP/2 traffic with AWS WAF enabled and update the target group attributes as described in the AWS Elastic Load Balancing documentation for WAF HTTP/2 inspection.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
Amazon Web ServicesAws Wafapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

8 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

8 SOURCESView more in app
What this page doesn’t show

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Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity6

Community discussion across Reddit, Mastodon, and other social sources.

EXTERNAL REFERENCES
MITRE CVE
cve.org · CVE-2026-13763
NVD
nvd.nist.gov/vuln/detail/CVE-2026-13763
MITRE CWE · CWE-444
cwe.mitre.org