CoopCycle coopcycle-web 5.6.0 before 6.20.0 Missing Zelty Webhook Signature Verification
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 6.20.0
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 6.20.0.
- Exploitation0/40No signal
- Exposure17/25No login or user action needed, reachable over the network without a login · Data gap: Advisories don't say whether default setups are affected
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity8.3/10CVSS 8.3
- No patch0/5No signal
What would change the score
- Would score about 70 if added to CISA KEV
- Would score about 65 if CISA's SSVC rates exploitation active
- Would score about 30 if advisories confirm default setups are exposed
CVE-2026-121620 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.3 (high) and affects coopcycle-web; fixed in 6.20.0.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 25/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Unclear
- Fix
- Fixed in 6.20.0
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
The CoopCycle coopcycle-web software is affected by a missing signature check in its Zelty webhook handler, which lets an attacker remotely, without logging in, send forged events to the webhook endpoints. Those forged events can toggle restaurant products and change order preparation states.
Read the original description
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 to do
Upgrade to a fixed version: 6.20.0.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- CoopCycle coopcycle-web
From 5.6.0 · fixed in 6.20.0
Evidence 5
- Patch
- Repository
- Repository
- Repository
- Link
Corrections
None so far.
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Questions about CVE-2026-121620
Is CVE-2026-121620 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
The Zelty webhook endpoints did not check request signatures when the webhook secret was left empty, so forged events could be accepted. Attackers could use this to toggle restaurant products and alter order preparation states.Source: vulncheck.com, github.com
Which versions are affected by CVE-2026-121620?
coopcycle-web: from 5.6.0 before 6.20.0.Source: cve.now feed data
Am I affected, and how do I check?
coopcycle-web versions from 5.6.0 up to but not including 6.20.0 are in the affected range. The exposure depends on the ZELTY_WEBHOOK_SECRET setting, which previously skipped signature verification when left empty. Check the installed coopcycle-web version and whether ZELTY_WEBHOOK_SECRET is empty.Source: vulncheck.com, github.com
How do I fix CVE-2026-121620?
Upgrade coopcycle-web to 6.20.0 or later, the first version outside the affected range.Source: vulncheck.com, github.com