CVE-2026-91080 adnanh CVE debrief

Who should care

Defenders responsible for the security of webhook service deployments should assess exposure and prioritize verification of the version in use. They should also consider implementing compensating controls, such as rate limiting or input validation, to mitigate the risk of exploitation. Security teams and vulnerability management teams should review the vulnerability and assess the potential impact on their systems.

Why it matters

CVE-2026-91080 is a high-severity vulnerability in the webhook service that allows unauthenticated attackers to cause a denial-of-service (DoS) condition. Defenders should prioritize verifying the version of the webhook service in use and assessing exposure to untrusted input.

• Potential service crashes due to out-of-memory conditions.
• Possible degradation of service performance due to oversized request bodies.
• Need for verification of webhook service version and exposure to untrusted input.
• Potential for denial-of-service (DoS) attacks.

Technical summary

The webhook service through version 2.8.3 reads the entire request body into memory before evaluating trigger rules, allowing unauthenticated attackers to exhaust memory by sending oversized bodies. This can lead to out-of-memory conditions and service crashes. The vulnerability can be exploited by sending multi-gigabyte request bodies with invalid signatures. Defenders should prioritize verifying the version of the webhook service in use and assessing exposure to untrusted input. They should also consider implementing compensating controls, such as rate limiting or input validation, to mitigate the risk of exploitation.

Defensive priority

Defenders should prioritize verifying the version of the webhook service in use and assessing exposure to untrusted input. They should also consider implementing compensating controls, such as rate limiting or input validation, to mitigate the risk of exploitation.

Recommended defensive actions

• Verify the version of the webhook service in use and assess exposure to untrusted input.
• Implement compensating controls, such as rate limiting or input validation, to mitigate the risk of exploitation.
• Monitor for unusual traffic patterns or service crashes that may indicate attempted exploitation.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its description, CVSS score, and references to source code and advisory information. The vulnerability is confirmed to exist in webhook service versions up to 2.8.3. Official CVE Program and NVD records offer source-provided metadata and vulnerability assessments. Additional source references are available for further review.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.