# CVE-2026-107276: MISP Email OTP Race Condition Allows One-Time Password to Be Consumed by Multiple Concurrent Requests

> Attackers can reuse a single email OTP to create multiple sessions due to a race condition, bypassing one-time use restrictions in MISP.

- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/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:** 7 Oct 2026
- **Updated:** 7 Oct 2026
- **Also known as:** GHSA-fjjq-85mx-vg3v

## What is CVE-2026-107276?

CVE-2026-107276 is a medium-severity vulnerability in MISP, published on 7 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

MISP contains a race condition in the email-based one-time password (OTP) login flow. When two HTTP requests carrying the same valid OTP are submitted concurrently, both can successfully authenticate and establish a session. The root cause is that the OTP value is read from the shared store, validated, and then deleted in separate non-atomic steps, allowing a second in-flight request to read the same value before the first request's deletion takes effect.

Preconditions:

- The target MISP instance has email OTP login enabled.

- The attacker possesses a valid, unexpired OTP (e.g., via email interception or social engineering).

- The attacker can issue two HTTP POST requests in close temporal proximity.

Impact:

- The one-time-use guarantee of the OTP is violated; a single code can yield two authenticated sessions.

- This weakens the authentication control and may facilitate unauthorized access if the OTP is shared or intercepted.

Affected versions: <2.5.48

Weakness: CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition), CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-107276?


## How do I fix CVE-2026-107276?

No fix has been published for CVE-2026-107276 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-107276 being exploited?

There is no known exploitation of CVE-2026-107276 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-107276 and fix it if it is affected.

What it is: CVE-2026-107276 is a medium-severity vulnerability in MISP, published on 7 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-2026-107276 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-2026-107276/ (Markdown: https://insights.sbomify.com/CVE-2026-107276/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-107276
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-107276
- OSV: https://osv.dev/vulnerability/CVE-2026-107276

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-107276/
Summaries are generated and may contain mistakes; the official description above is the record.