CVE-2026-121620CoopCycle coopcycle-web insufficient verification of data authenticity
CVE-2026-121620 is a insufficient verification of data authenticity in CoopCycle coopcycle-web, rated high (8.3 on CVSS 4.0).
Why this priority: High severity, with no exploitation signal yet.
Published · Updated · NVD status: Received
What it is
Data is accepted without proof it came from where it claims.
How it is reached
An attacker can exploit it over the network, without an account, and nobody has to click anything. Success also depends on conditions the attacker does not fully control.
What an attacker gains
A successful attack can change data or behaviour. In practice, this kind of flaw lets an attacker read or tamper with traffic, or pass a forged message as genuine.
Is it being exploited?
There is no public report of exploitation yet. EPSS estimates a 0.22% chance of exploitation activity in the next 30 days, higher than 13% of scored CVEs.
What to do
- Upgrade CoopCycle coopcycle-web to 6.20.0 or later.
- Until it is patched, keep it off the internet or behind a VPN, allowlist or authenticating proxy.
Description from NVD
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.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- TLS termination and service-to-service channels. The flaw sits on the network path between clients and services.
- Signature checks. The flaw sits on the network path between clients and services.
Trust boundaries in play
- Internet-facing entry points. No account is needed. Any instance reachable from outside your perimeter, through a load balancer, gateway, VPN or exposed admin port, is in scope.
- On the network path between clients and services. An attacker who crosses it can read or tamper with traffic, or pass a forged message as genuine.
Questions to answer about your own systems
- Where does CoopCycle coopcycle-web run in your systems, and at which version?
- Which of those instances can be reached from the internet or partner networks?
- What can it reach once compromised: which data stores, secrets and services?
Read more
Patches and commits
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.