Glances: REST API CORS Credentials Guard Uses Exact-Match Instead of Membership Test — Bypassed by Any Multi-Origin Allowlist Containing the Wildcard

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

EPSS

• CVE-2026-68517: 0.46% estimated exploitation activity in the next 30 days; percentile 39.90 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Glances's REST API server includes a documented safety check intended to guarantee that corscredentials=True can never be combined with an unrestricted CORS origin allowlist. The check compares the configured origin list to the wildcard using exact list equality (corsorigins == [""]) instead of a membership test. Any multi-entry origin configuration that merely includes "" alongside other origins (e.g. corsorigins=,https://trusted.example.com) bypasses the check entirely, while Starlette's underlying CORSMiddleware still treats the presence of "" anywhere in the list as "allow all origins" and reflects the request's actual Origin header together with Access-Control-Allow-Credentials: true. This allows any website to read a victim's authenticated Glances monitoring data — including full process lists with command-line arguments — by exploiting the browser's automatic replay of cached HTTP Basic Auth credentials in a cross-origin request. Details…

Published by the source

17 Aug 2026, 17:04 UTC

Last modified by the source

17 Aug 2026, 17:04 UTC

Source last checked

26 Oct 2026, 13:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-fp27-88fp-2phg

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# Patch Next advisory brief: CVE-2026-68517

Advisory: Glances: REST API CORS Credentials Guard Uses Exact-Match Instead of Membership Test — Bypassed by Any Multi-Origin Allowlist Containing the Wildcard
IDs: CVE-2026-68517, GHSA-fp27-88fp-2phg
Record: https://patchnext.com/advisories/cve-2026-68517 (revision 1, source checked 26 Oct 2026, 13:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: glances 4.5.6. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI glances: affected < 4.5.6; fixed in 4.5.6

## Suggested inspection (read-only)
- `python -m pip show glances`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on glances.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-fp27-88fp-2phg (GitHub-reviewed advisory GHSA-fp27-88fp-2phg lists affected ranges: PyPI glances >=0 <4.5.6)

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