# CVE-2025-15079: libssh global known_hosts override

> libcurl may bypass host key verification by accepting hosts from the global known_hosts file instead of the specified one during SSH transfers.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/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:** Yes
- **Published:** 8 Jan 2026
- **Updated:** 15 Sep 2026
- **Also known as:** CLSA-2026-1771501223, CLSA-2026-1771501913, CURL-CVE-2025-15079, DEBIAN-CVE-2025-15079, ECHO-77ba-e0af-7bbd, GHSA-7q9p-cx8r-rh2q, JLSEC-2026-430, MINI-vcq9-jwg7-42gr, ROOT-OS-DEBIAN-12-CVE-2025-15079, ROOT-OS-DEBIAN-13-CVE-2025-15079, UBUNTU-CVE-2025-15079

## What is CVE-2025-15079?

CVE-2025-15079 is a medium-severity vulnerability in Haxx Curl, published on 8 Jan 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

When doing SSH-based transfers using either SCP or SFTP, and setting the
known_hosts file, libcurl could still mistakenly accept connecting to hosts
*not present* in the specified file if they were added as recognized in the
libssh *global* known_hosts file.

Weakness: CWE-297 (Improper Validation of Certificate with Host Mismatch)

## Which versions are affected by CVE-2025-15079?

It affects 1 product.


Products: Haxx Curl.

## How do I fix CVE-2025-15079?

Upgrade to a fixed version.

## Is CVE-2025-15079 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-15079 exists.

## Other vulnerabilities in Haxx Curl

- [CVE-2026-19931](https://insights.sbomify.com/CVE-2026-19931/): Negotiate ambient user conn reuse (critical 9.8)
- [CVE-2026-10536](https://insights.sbomify.com/CVE-2026-10536/): HTTP/2 stream-dependency tree UAF (critical 9.8)
- [CVE-2026-11856](https://insights.sbomify.com/CVE-2026-11856/): cross-origin Digest auth state leak (critical 9.8)
- [CVE-2026-8925](https://insights.sbomify.com/CVE-2026-8925/): SASL double-free (critical 9.8)
- [CVE-2026-9079](https://insights.sbomify.com/CVE-2026-9079/): stale proxy password leak (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-15079 and fix it if it is affected.

What it is: CVE-2025-15079 is a medium-severity vulnerability in Haxx Curl, published on 8 Jan 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: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-15079 exists.

Affected product: Haxx Curl. 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-2025-15079/ (Markdown: https://insights.sbomify.com/CVE-2025-15079/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-15079
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-15079
- OSV: https://osv.dev/vulnerability/CVE-2025-15079

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-15079/
Summaries are generated and may contain mistakes; the official description above is the record.