# CVE-2026-32616: Pigeon has a Host Header Injection in email verification flow

> Attackers can manipulate the Host header to redirect email verification links, potentially stealing tokens and taking over user accounts.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 13 Mar 2026
- **Updated:** 16 Mar 2026
- **Also known as:** GHSA-rrj4-9wgq-prcr

## What is CVE-2026-32616?

CVE-2026-32616 is a high-severity vulnerability in kasuganosoras Pigeon, published on 13 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Pigeon is a message board/notepad/social system/blog. Prior to 1.0.201, the application uses $_SERVER['HTTP_HOST'] without validation to construct email verification URLs in the register and resendmail flows. An attacker can manipulate the Host header in the HTTP request, causing the verification link sent to the user's email to point to an attacker-controlled domain. This can lead to account takeover by stealing the email verification token. This vulnerability is fixed in 1.0.201.

Weakness: CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2026-32616?


## How do I fix CVE-2026-32616?

No fix has been published for CVE-2026-32616 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-32616 being exploited?

There is no known exploitation of CVE-2026-32616 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-32616 and fix it if it is affected.

What it is: CVE-2026-32616 is a high-severity vulnerability in kasuganosoras Pigeon, published on 13 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-32616 in the wild and no public exploit code.

Affected product: kasuganosoras Pigeon. 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-2026-32616/ (Markdown: https://insights.sbomify.com/CVE-2026-32616/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-32616
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-32616
- OSV: https://osv.dev/vulnerability/CVE-2026-32616

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-32616/
Summaries are generated and may contain mistakes; the official description above is the record.