# CVE-2026-109426: Telegram-Stremio 5.1.0 Insecure Session Storage via encode_string

> Attackers with database access can recover the operator's Telegram session string due to weak encoding, allowing full account takeover.

- **Severity:** High 8.2 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/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:** 12 Oct 2026
- **Updated:** 13 Oct 2026
- **Also known as:** GHSA-f4vq-cf7c-pvmv

## What is CVE-2026-109426?

CVE-2026-109426 is a high-severity vulnerability in weebzone Telegram-Stremio, published on 12 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Telegram-Stremio through 5.1.0 contains an insecure storage vulnerability that allows attackers with access to the MongoDB database, backups, or logs to recover the operator's authenticated Telegram session string, which is protected only by a keyless, reversible encoding transform rather than actual encryption. Attackers can round-trip the stored value through the repository's own decode_string function with no secret key to obtain a fully authenticated Telegram session, granting complete control of the operator's Telegram account even when two-step verification is enabled.

Weakness: CWE-312 (Cleartext Storage of Sensitive Information)

## Which versions are affected by CVE-2026-109426?


## How do I fix CVE-2026-109426?

No fix has been published for CVE-2026-109426 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-109426 being exploited?

There is no known exploitation of CVE-2026-109426 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-109426 and fix it if it is affected.

What it is: CVE-2026-109426 is a high-severity vulnerability in weebzone Telegram-Stremio, published on 12 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-2026-109426 in the wild and no public exploit code.

Affected product: weebzone Telegram-Stremio. 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-2026-109426/ (Markdown: https://insights.sbomify.com/CVE-2026-109426/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-109426
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-109426
- OSV: https://osv.dev/vulnerability/CVE-2026-109426

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-109426/
Summaries are generated and may contain mistakes; the official description above is the record.