MyBooks: Unauthenticated Registration Bypass via Missing Server-Side ALLOW_REGISTER Enforcement
Published Aug 19, 2026
6.9
MEDIUMCVSS 4.0
EPSS 0.71%
Description
MyBooks is anebook management web server also known as Talebook. In 3.41.2 and earlier, the SignUp.post handler for POST /api/user/sign_up in webserver/handlers/user.py does not enforce the ALLOW_REGISTER configuration flag, even though the frontend hides registration controls when the flag is false. An unauthenticated remote attacker can call the endpoint directly and create a valid account on an instance whose administrator disabled public registration. The process_auth_header function in webserver/handlers/base.py also does not verify the account's active flag, so the newly created and unactivated account can authenticate immediately and access user-level API functionality. The bypass defeats the intended account-creation policy and can supply the low-privilege account required by related authorization vulnerabilities. This issue is fixed in version 3.42.0.
Affected products
-
- Version < 3.42.0StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| PoxenStudio | Talebook | n/a |
|
No data.
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
1 other source (NVD) ▾
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/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
No CVSS v3.1 score for this CVE.
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
PoCAutomatable
NoTechnical Impact
PartialDecision
n/aAssessed Aug 19, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 3, 2026.
Score over time
Aug–Oct 2026- EPSS v5
Percentile over time
- EPSS v5
Table of values (2 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 3, 2026 | 0.71% (0.00707) | 51.77th | v5 (v2026.06.15) |
| Aug 20, 2026 | 0.52% (0.00518) | 41.92th | v5 (v2026.06.15) |
References (3)
- https://github.com/PoxenStudio/mybooks/commit/a1780c98b00566af7da2fc099fe38500efc02e92 x_refsource_MISC
- https://github.com/PoxenStudio/mybooks/releases/tag/3.42.0 x_refsource_MISC
- https://github.com/PoxenStudio/mybooks/security/advisories/GHSA-3q85-5vj5-qx5v exploitx_refsource_CONFIRM
| Link | Providers | Tags |
|---|---|---|
| https://github.com/PoxenStudio/mybooks/commit/a1780c98b00566af7da2fc099fe38500efc02e92 | x_refsource_MISC | |
| https://github.com/PoxenStudio/mybooks/releases/tag/3.42.0 | x_refsource_MISC | |
| https://github.com/PoxenStudio/mybooks/security/advisories/GHSA-3q85-5vj5-qx5v | exploitx_refsource_CONFIRM |
Change history (0)
No recorded changes yet.