# CVE-2026-89035: MikroTik RouterOS 7.24.5 WebFig Session Token Replay Authentication Bypass


- **Severity:** Critical 9.1 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 21 Oct 2026
- **Updated:** 28 Oct 2026
- **Also known as:** GHSA-j7mx-6943-qw55

## What is CVE-2026-89035?

CVE-2026-89035 is a critical vulnerability in MikroTik RouterOS, published on 21 Oct 2026. 

### Official description

MikroTik RouterOS through 7.24.5 contains a session token replay vulnerability in the WebFig interface that allows attackers to bypass authentication by replaying captured session tokens across new ECDH sessions. The makeSessionKey function in libucrypto.so generates tokens using fixed salts without incorporating channel-specific or session-specific input, and the user service validates tokens against the login store without verifying channel context, enabling stolen tokens to grant persistent administrative access until the token store is explicitly cleared. This vulnerability extends the impact of CVE-2025-61481, which identified the underlying transport-layer exposure without a corresponding fix.

Weakness: CWE-613 (DEPRECATED: Insufficient Session Expiration)

## Which versions are affected by CVE-2026-89035?


## How do I fix CVE-2026-89035?

No fix has been published for CVE-2026-89035 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-89035 being exploited?

There is no known exploitation of CVE-2026-89035 in the wild and no public exploit code.

Public exploit code:

- Offline Python detector for CVE-2026-89035 exposure in MikroTik RouterOS inventories, with CSV/JSON input and auditable reports. (github_poc): https://github.com/mehmet-emir-eroglu/CVE-2026-89035

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89035 and fix it if it is affected.

What it is: CVE-2026-89035 is a critical vulnerability in MikroTik RouterOS, published on 21 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-89035 in the wild and no public exploit code.

Affected product: MikroTik RouterOS. 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-2026-89035/ (Markdown: https://insights.sbomify.com/CVE-2026-89035/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89035
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89035
- OSV: https://osv.dev/vulnerability/CVE-2026-89035

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89035/
Summaries are generated and may contain mistakes; the official description above is the record.