CVE-2026-101050 heymrun CVE debrief

Who should care

Defenders responsible for the security of Heym installations should assess their exposure and take necessary actions to prevent exploitation. This includes verifying the affected version of Heym, reviewing workflows, and applying necessary patches. Additionally, defenders should monitor for suspicious activity on Telegram webhook endpoints and review compensating controls for exposed systems.

Why it matters

CVE-2026-101050 is a high-severity vulnerability in Heym that allows remote unauthenticated attackers to post forged Telegram updates, triggering workflows with the owner's configured credentials and executing actions on attacker-supplied input. Defenders should prioritize verifying the affected version of Heym and applying the necessary patches to prevent exploitation.

• Remote unauthenticated attackers can post forged Telegram updates.
• Trigger workflows with the owner's configured credentials.
• Execute actions on attacker-supplied input.

Technical summary

The vulnerability occurs when the X-Telegram-Bot-Api-Secret-Token header is not verified on Telegram webhook endpoints if the credential_id is absent or the secret_token is empty. This allows remote unauthenticated attackers to post forged Telegram updates, triggering workflows with the owner's configured credentials and executing actions on attacker-supplied input. The affected product is Heym, and defenders should prioritize verifying the affected version and applying necessary patches to prevent exploitation. The vulnerability has a CVSS score of 8.3 and is considered high-severity.

Defensive priority

Defenders should prioritize verifying the affected version of Heym and applying the necessary patches to prevent exploitation.

Recommended defensive actions

• Verify the version of Heym in use and determine if it is vulnerable.
• Apply the necessary patches to update Heym to version 0.0.53 or later.
• Monitor for suspicious activity on Telegram webhook endpoints.
• Review and update workflows to ensure they are not executing actions on attacker-supplied input.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.

Evidence notes

The vulnerability was reported by Vulncheck and is tracked under CVE-2026-101050. The affected version of Heym is before 0.0.53. Defenders should verify the affected version of Heym and review workflows to ensure they are not executing actions on attacker-supplied input. This vulnerability allows remote unauthenticated attackers to post forged Telegram updates, triggering workflows with the owner's configured credentials and executing actions on attacker-supplied input.

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.