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Fencer Vulns
medium 5.4

CVE-2026-39401 json

Privilege Escalation via update_event Job Output in Cronicle

published 2026-04-07 7 mo ago modified 2026-07-20 3 mo ago also EUVD-2026-19925

cvss
5.4
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 8%
public exploits
0
none known

Summary

Cronicle is a multi-server task scheduler and runner, with a web based front-end UI. Prior to 0.9.111, jb child processes can include an update_event key in their JSON output. The server applies this directly to the parent event's stored configuration without any authorization check. A low-privilege user who can create and run events can modify any event property, including webhook URLs and notification emails. This vulnerability is fixed in 0.9.111.

Patch / fix

  • cronicle cronicle 0.9.111

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/jhuckaby/Cronicle/security/advisories/GHSA-5j3v-cq96-xw6v referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 5.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
CNA 4.0 5.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Affected products

  • jhuckaby Cronicle

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.