---
title: "CVE-2015-9258\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-2015-9258?format=md
keywords: index, follow
---

# CVE-2015-9258

Publication date 31 March 2018

Last updated 17 July 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**7.5 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2015-9258?format=md#impact-score)

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## Description

In Docker Notary before 0.1, gotuf/signed/verify.go has a Signature
Algorithm Not Matched to Key vulnerability. Because an attacker controls
the field specifying the signature algorithm, they might (for example) be
able to forge a signature by forcing a misinterpretation of an RSA-PSS key
as Ed25519 elliptic-curve data.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| notary | 18.04 LTS bionic | Not affected |
| 17.10 artful | Not affected |
| 16.04 LTS xenial | Not affected |
| 14.04 LTS trusty | Not in release |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

7.5 · High

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 7.5 · High |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-9258)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2015-9258)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2015-9258)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2015-9258)

### Other references

* <https://docs.docker.com/notary/changelog/>
* <https://github.com/theupdateframework/notary/blob/master/docs/resources/ncc_docker_notary_audit_2015_07_31.pdf>
* <https://www.cve.org/CVERecord?id=CVE-2015-9258>