# CVE-2026-104445: YesWiki before 4.6.7 Authentication Bypass via ActivityPub Inbox Actor Spoofing

> Unauthenticated attackers can delete or overwrite federated entries in YesWiki by spoofing ActivityPub actors due to missing signature binding.

- **Severity:** High 8.8 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/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:** 2 Oct 2026
- **Updated:** 6 Oct 2026
- **Also known as:** GHSA-px48-25j6-h73c, GHSA-rm6r-grfg-4v78

## What is CVE-2026-104445?

CVE-2026-104445 is a high-severity authentication bypass vulnerability in yeswiki, published on 2 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

YesWiki before 4.6.7 contains an authentication bypass vulnerability in the ActivityPub inbox that fails to bind the verified HTTP signature signer to the activity actor. Unauthenticated attackers with any ActivityPub keypair can send signed Delete or Update activities referencing a mirrored entry's sourceUrl to delete or overwrite other actors' federated entries.

Weakness: CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2026-104445?


## How do I fix CVE-2026-104445?

No fix has been published for CVE-2026-104445 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-104445 being exploited?

There is no known exploitation of CVE-2026-104445 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-104445 and fix it if it is affected.

What it is: CVE-2026-104445 is a high-severity authentication bypass vulnerability in yeswiki, published on 2 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-2026-104445 in the wild and no public exploit code.

Affected product: yeswiki. 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-2026-104445/ (Markdown: https://insights.sbomify.com/CVE-2026-104445/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-104445
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-104445
- OSV: https://osv.dev/vulnerability/CVE-2026-104445

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-104445/
Summaries are generated and may contain mistakes; the official description above is the record.