TI-2026-76798 Aliases CVE-2026-113349 GHSA-5q4v-58r2-wwvg

Missing authorization in OpenCATS calendar edit and delete

LOW 24CWE-639Published 2026-10-20 · Updated 2026-10-22

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: Security bypass
Confidentiality · integrity · availability: None · Low · None
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-639.

Summary

OpenCATS before 0.10.0 has a missing authorization flaw in the calendar event edit and delete handlers, which do not check that the event belongs to the requesting user. An authenticated user with EDIT or DELETE access can supply arbitrary event IDs to change or remove other users' calendar events, including events restricted to their owner. The flaw is tracked as CWE-639, authorization bypass through a user-controlled key.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

OpenCATS before 0.10.0 contains a missing authorization vulnerability in CalendarUI::onEditEvent() and onDeleteEvent() that allows authenticated users to modify or delete other users' calendar events. Attackers with EDIT or DELETE access can supply arbitrary eventID values to alter or remove any user's events, including non-public ones restricted to their owner.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00261 17th percentileScored 2026-11-07

Fix Fixed OpenCATS (opencats): 0.10.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
opencats	OpenCATS	before 0.10.0	0.10.0	Patch available	CNA

OpenCATS Vendoropencats Affected before 0.10.0 Fixed in 0.10.0 Patch available CNA

Remediation

Upgrade OpenCATS to version 0.10.0, which fixes the issue.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Fix · CNA OpenCATS (opencats) Fixed in 0.10.0

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

Release · 2026-10-20
OpenCATS 0.10.0
6 records Highest priority Priority LOW 6 LOW
Other records, highest priority first
- TI-2026-76797 Missing authorization in OpenCATS EEO reports exposes demographic dataPriority LOW 24
- TI-2026-76796 Missing authorization in OpenCATS import revert action lets users delete recordsPriority LOW 24
- TI-2026-76795 Missing authorization in OpenCATS saved-list AJAX endpointsPriority LOW 24
Show all 6 records →

Timeline

2026-10-20 Threatist record created from CVE-2026-113349
2026-10-20 Alias added: GHSA-5q4v-58r2-wwvg
2026-10-23 CISA SSVC decision points changed

References

Patch 1

https://github.com/opencats/OpenCATS/commit/aa3b414c3672f5010ca26c44192aa8e72d3735bd

Other 5

TI-2021-22549 OpenCATS 0.9.4 Remote Code Execution via Resume Upload CVSS 4.0CRITICAL 9.3
TI-2026-22120 OpenCATS PHP Code Injection via installer AJAX endpoint CVSS 4.0CRITICAL 9.2
TI-2026-36639 OpenCATS - SQL Injection in DataGrid sortDirection Parameter CVSS 4.0HIGH 8.4
TI-2023-12031 Cross-site scripting in OpenCATS CVSS 3.1MEDIUM 6.1
TI-2023-12032 Cross-site scripting in OpenCATS CVSS 3.1MEDIUM 5.4
TI-2023-12030 Open redirect in OpenCATS CVSS 3.1MEDIUM 5.4

See all 37 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences