Exploit discussion active in current signal (1 latest mentions)
Recommended action window: High priority (within 72h)
NVD description
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.
Priority
LOW
Exploitation
NONE
PoC
YES
Patch
AVAILABLE
Momentum
STABLE
If you run products in this scope, you should treat this CVE as relevant to your environment.
| Date | Total | Labels |
|---|
| 2026-03-26 | 2 | Disclosure1General1 |
| 2026-03-27 | 1 | PoC1 |
Warning: #OTP codes generated in #Outline are susceptible to #bruteforce attacks as no amount or frequency limitation of invalid attempts is implemented. A #PoC is available for the critical #CVE-2026-33640, exploitation can lead to account compromise. #Patch #Patch #Patch
Post summary
OTP codes in Outline are vulnerable to brute‑force attacks; a PoC for CVE‑2026‑33640 exists that can compromise accounts, and a patch is recommended.
CVE-2026-33640 Outline is a service that allows for collaborative documentation. Outline implements an Email OTP login flow for users not associated with an Identity Provider. Start… https://www.cve.org/CVERecord?id=CVE-2026-33640
Post summary
The snippet merely references a CVE record for Outline’s Email OTP flow without providing details on exploitation, mitigation, or technical specifics.
🚨 CVE-2026-33640: Outline has a rate limit bypass ... Rate limiter bypass + infinite OTP attempts = trivial account takeover against any Outline instance running 0.86.0-1.5.... https://zerodaysignal.com/vulnerability/CVE-2026-33640 #netsec #vulnerability #CVE #sysadmin #zeroday
Post summary
The post reveals a rate‑limiter bypass in Outline 0.86.0‑1.5 that enables infinite OTP attempts, making account takeover trivial for affected versions.
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| Part | Vendor | Product | Version | Target SW | Target HW |
|---|---|---|---|---|---|
| App | getoutline | outline | - | - | - |