---
title: "CVE-2025-27809\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2025-27809?format=md
keywords: index, follow
---

# CVE-2025-27809

Publication date 25 March 2025

Last updated 8 October 2025

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**5.4 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2025-27809?format=md#impact-score)

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## Description

Mbed TLS before 2.28.10 and 3.x before 3.6.3, on the client side, accepts
servers that have trusted certificates for arbitrary hostnames unless the
TLS client application calls mbedtls\_ssl\_set\_hostname.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| mbedtls | 26.04 LTS resolute | Not affected |
| 25.10 questing | Ignored end of life, was needed |
| 25.04 plucky | Ignored end of life, was needed |
| 24.10 oracular | Ignored end of life, was needs-triage |
| 24.04 LTS noble | Ignored changes too intrusive |
| 22.04 LTS jammy | Ignored changes too intrusive |
| 20.04 LTS focal | Ignored end of standard support, was needs-triage |
| 18.04 LTS bionic | Ignored changes too intrusive |
| 16.04 LTS xenial | Ignored end of ESM support, was ignored [changes too intrusive] |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)
* [Patch details](https://ubuntu.com/security/CVE-2025-27809?format=md#patch-details)

### Patch details

For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)

| Package | Patch details |
| --- | --- |
| mbedtls | * Upstream:   [e61852e](https://github.com/Mbed-TLS/mbedtls/commit/e61852e4d2fabe9f37d38242050f26e8508ad8ec) * Upstream:   [6b88594](https://github.com/Mbed-TLS/mbedtls/commit/6b8859467c2c1142c31a8d0add0b5b6cdd49c4e1) * Upstream:   [0178dc9](https://github.com/Mbed-TLS/mbedtls/commit/0178dc9946e92adfb53dfada5bbd993e38c0fc3e) * Upstream:   [7656ad7](https://github.com/Mbed-TLS/mbedtls/commit/7656ad7b9fc7792f9269f2762bd7af96e51cae0c) * Upstream:   [2c33c75](https://github.com/Mbed-TLS/mbedtls/commit/2c33c757256a305d4c7f60c189248b29d6a0efa1) * Upstream:   [1f6864b](https://github.com/Mbed-TLS/mbedtls/commit/1f6864b174788eef565ff10f895671beefd14c77) * Upstream:   [3a2f75d](https://github.com/Mbed-TLS/mbedtls/commit/3a2f75d8d59bc0c3f5a15bc13efa22fef0b8c55e) * Upstream:   [f33c45f](https://github.com/Mbed-TLS/mbedtls/commit/f33c45f84d52c49d985063e41f15998e84133e90) * Upstream:   [63f958d](https://github.com/Mbed-TLS/mbedtls/commit/63f958df772f763dfd5b6d0506f9cac9ed34c34e) * Upstream:   [ae59c52](https://github.com/Mbed-TLS/mbedtls/commit/ae59c5232274df36b1b58dd52eb74cb153829a1a) * Upstream:   [551756d](https://github.com/Mbed-TLS/mbedtls/commit/551756df7c5d76736883db37b8d43284bc622bb2) * Upstream:   [18b52ce](https://github.com/Mbed-TLS/mbedtls/commit/18b52ce40c3f0beae806a1f38401fbd7f5c3f3d7) |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

5.4 · Medium

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | High |
  | Privileges required | None |
  | User interaction | None |
  | Scope | Changed |
  | Confidentiality impact | Low |
  | Integrity impact | Low |
  | Availability impact | None |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 5.4 · Medium |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-27809)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2025-27809)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2025-27809)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2025-27809)

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2025-27809>
* <https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2025-03-1/>