8.3
HIGH CVSS 4.0
CVE-2026-100678
stoatchat before 0.15.5 MFA Brute Force via Insufficient Rate Limiting
Description

stoatchat before 0.15.5 fails to enforce account-level attempt limits on MFA login challenges, allowing attackers who know a password to guess TOTP codes with only IP-based rate limiting. Attackers can reuse MFA challenge tickets across multiple failed attempts and distribute guesses across IP addresses to bypass rate limiting and gain account access.

INFO

Published Date :

Sept. 26, 2026, 2:16 p.m.

Last Modified :

Sept. 26, 2026, 2:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-100678 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 MEDIUM MITRE-CVE
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 HIGH [email protected]
Solution
Update to a version of stoatchat that enforces account-level MFA attempt limits.
  • Update stoatchat to version 0.15.5 or later.
  • Enforce account-level MFA attempt limits.
  • Implement stricter rate limiting for MFA challenges.
  • Review and enhance authentication security controls.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-100678.

URL Resource
https://github.com/stoatchat/stoatchat/security/advisories/GHSA-6877-g673-f5r8
https://www.vulncheck.com/advisories/stoatchat-before-0.15.5-mfa-brute-force-via-insufficient-rate-limiting
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-100678 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-100678 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-100678 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Sep. 26, 2026

    Action Type Old Value New Value
    Added Description stoatchat before 0.15.5 fails to enforce account-level attempt limits on MFA login challenges, allowing attackers who know a password to guess TOTP codes with only IP-based rate limiting. Attackers can reuse MFA challenge tickets across multiple failed attempts and distribute guesses across IP addresses to bypass rate limiting and gain account access.
    Added CVSS V4.0 AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/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
    Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
    Added CWE CWE-307
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/100xxx/CVE-2026-100678.json">CVE-2026-100678</a>
    Added Reference https://github.com/stoatchat/stoatchat/security/advisories/GHSA-6877-g673-f5r8
    Added Reference https://www.vulncheck.com/advisories/stoatchat-before-0.15.5-mfa-brute-force-via-insufficient-rate-limiting
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.