cronmaster: Improper Authentication
CVE-2026-34072 is a critical-severity improper authentication vulnerability in cronmaster from Fccview, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected cronmaster versions: < 2.2.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.46% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of cronmaster you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Fccview | cronmaster | < 2.2.0 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.3 | High | CNA (github.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
Cr*nMaster (cronmaster) is a Cronjob management UI with human readable syntax, live logging and log history for cronjobs. Prior to version 2.2.0, an authentication bypass in middleware allows unauthenticated requests with an invalid session cookie to be treated as authenticated when the middleware’s session-validation fetch fails. This can result in unauthorized access to protected pages and unauthorized execution of privileged Next.js Server Actions. This issue has been patched in version 2.2.0.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
How developers prevent this class of flaw
- Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- github.com/fccview/cronmaster/releases/tag/2.2.0Release Notes
Recent Improper Authentication vulnerabilities
- 9.8 Critical severity
- 8.2 High severity
- 9.1 Critical severity
- 9.8 Critical severity
- 7.1 High severity
- 9.8 Critical severity
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