# CVE-2026-102354: BentoPDF: SSRF via DNS Rebinding (TOCTOU) in Cloudflare CORS Proxy Worker

> Attacker can exploit DNS rebinding in BentoPDF's Cloudflare proxy to access internal network resources when proxy secret validation is disabled.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Oct 2026
- **Updated:** 15 Oct 2026
- **Also known as:** GHSA-wh78-rcw2-hhg9

## What is CVE-2026-102354?

CVE-2026-102354 is a medium-severity server-side request forgery vulnerability in alam00000 bentopdf, published on 14 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

BentoPDF is a privacy-focused PDF toolkit that runs in the browser. In versions through 2.8.6, cloudflare/cors-proxy-worker.js performs a DNS-over-HTTPS safety check in hostnameResolvesToPrivate(), as used by isValidCertificateUrl() and isValidTsaUrl(), separately from the outbound fetch(targetUrl, ...). In deployments where PROXY_SECRET validation is not enabled, a direct client that controls authoritative DNS can forge the Origin header, supply a certificate, OCSP, CRL, or TSA URL that passes the proxy's accepted path checks, return a public address during validation, and return a private or link-local address during the later fetch. The endpoint can return allowed response bodies to the attacker, but exploitation requires precise timing, redirects and IP-literal obfuscation are blocked, and network reachability limits the target. This vulnerability is fixed in 2.8.7.

Weakness: CWE-918 (Server-Side Request Forgery), CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition)

## Which versions are affected by CVE-2026-102354?


## How do I fix CVE-2026-102354?

No fix has been published for CVE-2026-102354 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-102354 being exploited?

There is no known exploitation of CVE-2026-102354 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-102354 and fix it if it is affected.

What it is: CVE-2026-102354 is a medium-severity server-side request forgery vulnerability in alam00000 bentopdf, published on 14 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-2026-102354 in the wild and no public exploit code.

Affected product: alam00000 bentopdf. 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-2026-102354/ (Markdown: https://insights.sbomify.com/CVE-2026-102354/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-102354
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-102354
- OSV: https://osv.dev/vulnerability/CVE-2026-102354

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-102354/
Summaries are generated and may contain mistakes; the official description above is the record.