Juju: In-Memory Token Store for Discharge Tokens Lacks Concurrency Safety and Persistence

Exploitation

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

CVSS 4.0

6.1 · CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-5774: 0.24% estimated exploitation activity in the next 30 days; percentile 15.60 (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 The localLoginHandlers struct in the Juju API server maintains an in-memory map to store discharge tokens following successful local authentication. This map is accessed concurrently from multiple HTTP handler goroutines without any synchronization primitive protecting it. The absence of a mutex or equivalent mechanism means that concurrent reads, writes, and deletes on the map can trigger Go runtime panics and may allow a discharge token to be consumed more than once before deletion completes. Details When a user authenticates through the local login flow, a discharge token is generated and stored in a plain map[string]string field named userTokens. The form handler writes to this map when authentication succeeds, and the third-party caveat checker reads from and deletes from the same map when a discharge request arrives. Both code paths execute inside goroutines dispatched by the HTTP server, meaning concurrent requests will access the map simultaneously. Go's runtime…

Published by the source

10 Apr 2026, 21:00 UTC

Last modified by the source

27 Apr 2026, 16:21 UTC

Source last checked

26 Oct 2026, 15:19 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-7m55-2hr4-pw78

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# Patch Next advisory brief: CVE-2026-5774

Advisory: Juju: In-Memory Token Store for Discharge Tokens Lacks Concurrency Safety and Persistence
IDs: CVE-2026-5774, GHSA-7m55-2hr4-pw78
Record: https://patchnext.com/advisories/cve-2026-5774 (revision 1, source checked 26 Oct 2026, 15:19 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/juju/juju 0.0.0-20260408003526-d395054dc2c3. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/juju/juju: affected < 0.0.0-20260408003526-d395054dc2c3; fixed in 0.0.0-20260408003526-d395054dc2c3

## Suggested inspection (read-only)
- Go github.com/juju/juju: check the installed version with your package manager.

## 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 github.com/juju/juju.
- 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-7m55-2hr4-pw78 (GitHub-reviewed advisory GHSA-7m55-2hr4-pw78 lists affected ranges: Go github.com/juju/juju >=0 <0.0.0-20260408003526-d395054dc2c3)

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