CVE-2026-5774Public exploitNetwork attack vector

API server crash and token replay via race

Published Apr 10, 2026 · Updated Apr 10, 2026

Race condition in Canonical Juju 2.9.56, 3.6.20, and 4.0.5 allows remote authenticated users to crash the API server. The localLoginHandlers userTokens map is read, written, and deleted by concurrent HTTP handler goroutines without a lock, and its read-then-delete sequence is not atomic. A valid discharge token and concurrent requests are required; exploitation terminates the API server or accepts the single-use token more than once.

CVSS severity6.0
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in Canonical Juju 2.9.56, 3.6.20, and 4.0.5 allows remote authenticated users to crash the API server. The localLoginHandlers userTokens map is read, written, and deleted by concurrent HTTP handler goroutines without a lock, and its read-then-delete sequence is not atomic. A valid discharge token and concurrent requests are required; exploitation terminates the API server or accepts the single-use token more than once.

The record

CVE
CVE-2026-5774
Published
Apr 10, 2026
Updated
Apr 10, 2026
Vendor
Canonical
Product
Juju
Classifications
CWE-362, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.0.0 <2.9.57
  2. Affected versionversion=3.0.0 <3.6.21
  3. Affected versionversion=4.0.0 <4.0.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Canonical · Jujuversion=2.0.0 <2.9.57; version=3.0.0 <3.6.21; version=4.0.0 <4.0.6

Published CVSS scores

6.1GitHub Security AdvisoryCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N
6.0Canonical Ltd.CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
6.4NIST NVDCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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