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CVE

CVE-2026-33640

Outline has a rate limit bypass that allows brute force of email login OTP
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CVE

CVE-2026-33640

Outline has a rate limit bypass that allows brute force of email login OTP

Outline is a service that allows for collaborative documentation. Outline implements an Email OTP login flow for users not associated with an Identity Provider. Starting in version 0.86.0 and prior to version 1.6.0, Outline does not invalidate OTP codes based on amount or frequency of invalid submissions, rather it relies on the rate limiter to restrict attempts. Consequently, identified bypasses in the rate limiter permit unrestricted OTP code submissions within the codes lifetime. This allows attackers to perform brute force attacks which enable account takeover. Version 1.6.0 fixes the issue.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
9.1
-
4.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/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
C
H
U
0
-
C
H
U
-

Related Resources

No items found.

References

https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33640.json, https://github.com/outline/outline/releases/tag/v1.6.0, https://github.com/outline/outline/security/advisories/GHSA-cwhc-53hw-qqx6, https://nvd.nist.gov/vuln/detail/CVE-2026-33640

Severity

0

CVSS Score
0
10

Basic Information

Ecosystem
Base CVSS
0
EPSS Probability
0.00054%
EPSS Percentile
0.17028%
Introduced Version
5bdabc13a608cd7f4fc897205bab905e957ec918
Fix Available
24954204eac2447b648d4e56813f69205ee4b873

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