CVE-2026-121620 PUBLISHED

CoopCycle coopcycle-web 5.6.0 before 6.20.0 Missing Zelty Webhook Signature Verification

Assigner: VulnCheck
Reserved: 03.11.2026 Published: 04.11.2026 Updated: 04.11.2026

CoopCycle coopcycle-web 5.6.0 before 6.20.0 contains a missing authentication vulnerability that allows unauthenticated attackers to forge Zelty webhook events because the x-zelty-hmac-sha256 HMAC signature is never verified. Attackers can POST forged dish, menu, option and order-status events to /api/zelty/webhook/* endpoints to toggle restaurant products and alter order preparation states.

CVSS Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N
CVSS Score: 8.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	High	Integrity	High	Integrity	None
Attack Requirements	Present	Availability	Low	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L
CVSS Score: 6.5

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	High
User Interaction	None	Availability Impact	Low

CVSS 3.1

Product Status

Vendor	CoopCycle
Product	coopcycle-web
Versions	Default: unaffected affected from 5.6.0 to 6.20.0 (excl.)

CVE-2026-121620 PUBLISHED

CoopCycle coopcycle-web 5.6.0 before 6.20.0 Missing Zelty Webhook Signature Verification

Metrics

Product Status

Credits

References

Problem Types