# CVE-2026-103655: MISP TOTP Code Replay Allows Duplicate Authentication Within Validity Period

> Attackers can replay captured TOTP codes to bypass two-factor authentication and access user accounts within the validity window.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Oct 2026
- **Updated:** 1 Oct 2026
- **Also known as:** GHSA-2hxj-rrwr-5g5v

## What is CVE-2026-103655?

CVE-2026-103655 is a critical authentication bypass vulnerability in MISP, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

MISP contains a vulnerability in its two-factor authentication (TOTP) verification process that permits a valid one-time code to be accepted more than once within its time-based validity window.

The issue exists in the user login flow where a TOTP code is verified as a second authentication factor. Because the system did not record whether a given TOTP period had already been consumed, the same code remained valid for its entire time window (typically 30 seconds). An attacker who captures a legitimate code during a user's login could replay it to authenticate a second session as that user.

Preconditions:

- The target user has TOTP-based two-factor authentication enabled.

- The attacker is in a position to observe or intercept the TOTP code during a legitimate login (e.g., network-level interception, shoulder surfing, or a compromised client).

- The replay must occur within the TOTP validity period.

Security impact:

- Unauthorized account access by replaying a captured one-time code.

- Potential compromise of threat-intelligence data and administrative functions accessible to the targeted user.

Affected versions: <v2.5.48.

Weakness: CWE-294 (Authentication Bypass by Capture-replay)

## Which versions are affected by CVE-2026-103655?


## How do I fix CVE-2026-103655?

No fix has been published for CVE-2026-103655 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-103655 being exploited?

There is no known exploitation of CVE-2026-103655 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-103655 and fix it if it is affected.

What it is: CVE-2026-103655 is a critical authentication bypass vulnerability in MISP, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-103655 in the wild and no public exploit code.

Affected product: MISP. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-103655/ (Markdown: https://insights.sbomify.com/CVE-2026-103655/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-103655
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-103655
- OSV: https://osv.dev/vulnerability/CVE-2026-103655

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-103655/
Summaries are generated and may contain mistakes; the official description above is the record.