# CVE-2026-64964: Generation of Predictable Email Confirmation Token in ATutor

> Attackers can predict email confirmation tokens to activate unconfirmed accounts, bypassing email verification and potentially taking over accounts.

- **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: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:** 20 Aug 2026
- **Updated:** 20 Aug 2026
- **Also known as:** GHSA-grqm-889w-4725

## What is CVE-2026-64964?

CVE-2026-64964 is a medium-severity authentication bypass vulnerability in ATutor, published on 20 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

ATutor generates predictable email confirmation tokens due to the use of insufficiently random values in the account confirmation functionality. Due to the use of predictable values related to user registration, an attacker who knows or can predict these values can guess valid account activation tokens. This allows an attacker to activate an unconfirmed account without access to the victim's email inbox.
Product is no longer actively supported and the vulnerabilities have not been fixed. Only version 2.2.4 was tested and confirmed as vulnerable, other versions were not tested but might also be vulnerable.

Weakness: CWE-340 (Generation of Predictable Numbers or Identifiers)

## Which versions are affected by CVE-2026-64964?


## How do I fix CVE-2026-64964?

No fix has been published for CVE-2026-64964 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-64964 being exploited?

There is no known exploitation of CVE-2026-64964 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-64964 and fix it if it is affected.

What it is: CVE-2026-64964 is a medium-severity authentication bypass vulnerability in ATutor, published on 20 Aug 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-2026-64964 in the wild and no public exploit code.

Affected product: ATutor. 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-2026-64964/ (Markdown: https://insights.sbomify.com/CVE-2026-64964/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64964
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64964
- OSV: https://osv.dev/vulnerability/CVE-2026-64964

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64964/
Summaries are generated and may contain mistakes; the official description above is the record.