# CVE-2026-118766: Botan: Online OCSP redirects enable blind requests to internal HTTP services


- **Severity:** Medium 6.1 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 29 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-9qgq-q9j4-4f82

## What is CVE-2026-118766?

CVE-2026-118766 is a medium-severity vulnerability in randombit botan, published on 29 Oct 2026. 

### Official description

Botan is a C++ cryptography library. Prior to 3.13.0, Botan's online OCSP client allowed a single HTTP redirect while posting an OCSP request to the URI in a certificate's Authority Information Access extension. A malicious OCSP responder or an on-path attacker could redirect the client to make one blind request to an otherwise unreachable internal HTTP service. The primary impact is blind SSRF that might affect internal services with non-idempotent GET handlers, and response timing can provide a coarse internal-service oracle. This issue is fixed in version 3.13.0.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-118766?


## How do I fix CVE-2026-118766?

No fix has been published for CVE-2026-118766 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-118766 being exploited?

There is no known exploitation of CVE-2026-118766 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-118766 and fix it if it is affected.

What it is: CVE-2026-118766 is a medium-severity vulnerability in randombit botan, published on 29 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-118766 in the wild and no public exploit code.

Affected product: randombit botan. 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-2026-118766/ (Markdown: https://insights.sbomify.com/CVE-2026-118766/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-118766
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-118766
- OSV: https://osv.dev/vulnerability/CVE-2026-118766

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-118766/
Summaries are generated and may contain mistakes; the official description above is the record.