Authenticated account impersonation via unchecked token owner
Published May 3, 2026 · Updated May 3, 2026
Improper authorization in Calibre-Web 0.6.26 and earlier allows remote authenticated users to obtain another user's Kobo access token. The generate_auth_token route in cps/kobo_auth.py trusted the user_id path value and returned or created that user's persistent token without verifying that it identified the logged-in user or an administrator. Any account able to reach the Kobo token endpoint can impersonate another Calibre-Web user through Kobo API requests; the flaw does not grant host-level access.
Summary
What happened
Improper authorization in Calibre-Web 0.6.26 and earlier allows remote authenticated users to obtain another user's Kobo access token. The generate_auth_token route in cps/kobo_auth.py trusted the user_id path value and returned or created that user's persistent token without verifying that it identified the logged-in user or an administrator. Any account able to reach the Kobo token endpoint can impersonate another Calibre-Web user through Kobo API requests; the flaw does not grant host-level access.
The record
- CVE
- CVE-2026-7709
- Published
- May 3, 2026
- Updated
- May 3, 2026
- Vendor
- Calibre-Web
- Product
- Calibre-Web
- Classifications
- CWE-285, CWE-266, T1550.001
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- May 3, 2026CVE publishedPublication date reported by the CVE source.
- May 3, 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.
- Affected versionversion=0.6.0
- Affected versionversion=0.6.1
- Affected versionversion=0.6.10
- Affected versionversion=0.6.11
- Affected versionversion=0.6.12
- Affected versionversion=0.6.13
- Affected versionversion=0.6.14
- Affected versionversion=0.6.15
- Affected versionversion=0.6.16
- Affected versionversion=0.6.17
- Affected versionversion=0.6.18
- Affected versionversion=0.6.19
- Affected versionversion=0.6.2
- Affected versionversion=0.6.20
- Affected versionversion=0.6.21
- Affected versionversion=0.6.22
- Affected versionversion=0.6.23
- Affected versionversion=0.6.24
- Affected versionversion=0.6.25
- Affected versionversion=0.6.26
- Affected versionversion=0.6.3
- Affected versionversion=0.6.4
- Affected versionversion=0.6.5
- Affected versionversion=0.6.6
- Affected versionversion=0.6.7
- Affected versionversion=0.6.8
- Affected versionversion=0.6.9
What conditions does exploitation require?
What is affected?
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.
Weakness, pattern, technique
Public exploit references
- CVE-2026-7709 proof of conceptproof of concept · unverified
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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