dbcve.org
Application Load BalancerApplication · Amazon

CVE-2026-13763

CRITICAL · 9.8 CVSS v3.1 Published 2026-06-29
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click 8 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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 )

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

AWS Application Load Balancer with AWS WAF enabled has a vulnerability where crafted HTTP/2 requests with fragmented body frames can bypass WAF managed rule body inspection. Attackers exploit inconsistent interpretation of HTTP/2 request handling to ensure only a partial request body is inspected by WAF, potentially allowing malicious payloads to slip through.

MitigationEnable the 'Inspect after sufficient data' target group configuration on affected ALBs to ensure WAF inspects the complete HTTP/2 request body before forwarding to targets.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Application Load BalancerApplication
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify ALBs with WAF enabled
    Run: aws elbv2 describe-load-balancers --query 'LoadBalancers[].LoadBalancerArn' and then check each for WAF association: aws wafv2 list-associated-resources --resource-arn <alb-arn>
    Affected if An ALB exists and has a WAF Web ACL associated via aws wafv2 list-associated-resources returning a WAF ACL ID
  2. Verify HTTP/2 is enabled on ALB listener
    Run: aws elbv2 describe-listeners --load-balancer-arn <alb-arn> --query 'Listeners[].Protocol'
    Affected if Listener Protocol returns 'HTTP2' or 'HTTPS' (HTTP/2 is enabled by default for HTTPS listeners)
  3. Confirm WAF rule has body inspection configured
    Run: aws wafv2 get-rule-group --name <waf-rule-name> --scope REGIONAL --id <rule-id> and inspect Rules[].Statement.ByteMatchStatement or Rules[].Statement.XssMatchStatement for 'FieldToMatch':{'Body':{}}
    Affected if WAF rule contains Body field to match configuration, indicating body inspection is active
  4. Check if Inspect after sufficient data is disabled
    Run: aws elbv2 describe-target-group-attributes --target-group-arn <target-group-arn> and look for attribute key 'enable_http2_inspect_after_sufficient_data' with value 'false' or the attribute is absent
    Affected if The attribute 'enable_http2_inspect_after_sufficient_data' is set to 'false' or does not exist, meaning only partial HTTP/2 body is inspected by WAF

User is affected if they have an ALB with WAF enabled, HTTP/2 is active, WAF is configured to inspect request body, and the Inspect after sufficient data setting is disabled or missing on the target group.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Enable the 'Inspect after sufficient data' target group configuration on affected ALBs to ensure WAF inspects the complete HTTP/2 request body before forwarding to targets.

Recommended fix High confidence
  1. Sign in to the AWS Management Console and navigate to EC2 > Target Groups
  2. Select the target group associated with your HTTP/2 Application Load Balancer
  3. Click on the 'Attributes' tab or select 'Edit attributes'
  4. Find the 'Inspect after sufficient data' setting and enable it
  5. Save the changes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Application Load Balancer Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,210
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-13763 in production — separate from our analysis above.

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  • Version or environment caveats, and links to real fixes
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