# CVE-2026-79310: Code injection in n/a

> Attacker can execute arbitrary Python code and OS commands via server-side template injection in web.py when using a writable precompiled template directory.

- **Severity:** High 8.5 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 23 Sep 2026
- **Updated:** 23 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-79310, GHSA-8m9w-mh94-cwr6, UBUNTU-CVE-2026-79310

## What is CVE-2026-79310?

CVE-2026-79310 is a high-severity code injection vulnerability in n/a, published on 23 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

webpy web.py 0.76 is vulnerable to server-side template injection (SSTI). The template engine can be tricked into executing attacker-controlled template code that built-in security checks are designed to reject. When an application precompiles templates from a directory the attacker can write to and later renders them through the precompiled template loader, the sandbox is bypassed and the attacker's code runs, resulting in arbitrary Python code execution and OS command execution on the server.

Weakness: CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2026-79310?


## How do I fix CVE-2026-79310?

No fix has been published for CVE-2026-79310 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-79310 being exploited?

There is no known exploitation of CVE-2026-79310 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-79310 and fix it if it is affected.

What it is: CVE-2026-79310 is a high-severity code injection vulnerability in n/a, published on 23 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-79310 in the wild and no public exploit code.

Affected product: n/a. 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-2026-79310/ (Markdown: https://insights.sbomify.com/CVE-2026-79310/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-79310
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-79310
- OSV: https://osv.dev/vulnerability/CVE-2026-79310

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-79310/
Summaries are generated and may contain mistakes; the official description above is the record.