CVE-2026-76878
HIGHDescription
In OpenStack Aodh before 22.0.1, the alarm list API bypasses project scoping when the all_projects query parameter is set to false. The API checks for the presence of the all_projects key rather than its value; a true value enforces the administrator-only policy, but a false value removes the key and skips the branch that normally restricts results to the caller's project. A non-admin user with the reader role can list alarms from all projects, exposing alarm actions containing trust webhook URLs, Heat signal endpoints, project IDs, and user IDs. The parameter can also be combined with a foreign project_id to target a specific project's alarms. A related concern is that OpenStack Watcher does not apply authorization to its webhook trigger endpoint. Any authenticated user who learns an audit's webhook URL, for example from this leaked Aodh alarm metadata, can start an EVENT audit and its associated action plan regardless of their own project or role. The webhook endpoint has lacked policy enforcement since its introduction in the Ussuri release (Watcher 4.0.0).
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v4 Vector
Exploitability
Impact
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:L/SI:H/SA:L/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
Exploit Intelligence
Low risk: more likely to be exploited than 39% of all known CVEs.
References
Related Vulnerabilities
Other CWE-688 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2026-33549 | Medium | 6.7 | 0.2% | - | Fix |
| CVE-2021-33713 | Medium | 5.5 | 0.2% | - | Fix |
| CVE-2026-12311 | Medium | 4.7 | 0.2% | - | Fix |
Common questions
How do I fix CVE-2026-76878?
Upgrade aodh on debian unstable to 22.0.0-3 or later.
Is CVE-2026-76878 being actively exploited?
Not that we know of. CVE-2026-76878 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.48% is the estimated probability that it will be exploited in the next 30 days. That is higher than 39% of all scored CVEs.
How severe is CVE-2026-76878?
CVE-2026-76878 has a CVSS v4 base score of 8.4, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-76878 affect?
Published advisories record a fix for aodh (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
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Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-08-21.