---
title: "CVE-2017-9526\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-2017-9526?format=md
keywords: index, follow
---

# CVE-2017-9526

Publication date 10 June 2017

Last updated 25 August 2025

---

Ubuntu priority

**Low**

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

## Cvss 3 Severity Score

**5.9 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2017-9526?format=md#impact-score)

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## Description

In Libgcrypt before 1.7.7, an attacker who learns the EdDSA session key
(from side-channel observation during the signing process) can easily
recover the long-term secret key. 1.7.7 makes a cipher/ecc-eddsa.c change
to store this session key in secure memory, to ensure that constant-time
point operations are used in the MPI library.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2017-9526?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| libgcrypt11 | 19.04 disco | Not in release |
| 18.10 cosmic | Not in release |
| 18.04 LTS bionic | Not in release |
| 17.10 artful | Not in release |
| 17.04 zesty | Not in release |
| 16.10 yakkety | Not in release |
| 16.04 LTS xenial | Not in release |
| 14.04 LTS trusty | Not affected |
| libgcrypt20 | 19.04 disco | Not affected |
| 18.10 cosmic | Not affected |
| 18.04 LTS bionic | Not affected |
| 17.10 artful | Not affected |
| 17.04 zesty | Fixed 1.7.6-1ubuntu0.1 |
| 16.10 yakkety | Fixed 1.7.2-2ubuntu1.1 |
| 16.04 LTS xenial | Fixed 1.6.5-2ubuntu0.3 |
| 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)
* [Patch details](https://ubuntu.com/security/CVE-2017-9526?format=md#patch-details)

## Notes

---

### [tyhicks](https://launchpad.net/~tyhicks)

EdDSA support was added in 1.6.0

### 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 |
| --- | --- |
| libgcrypt20 | * Upstream:   <https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=commit;h=f9494b3f258e01b6af8bd3941ce436bcc00afc56> * Upstream:   <https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=commit;h=91456759b887e153c4d4ce19538d478df260cab2> |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

5.9 · Medium

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 5.9 · Medium |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-9526)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2017-9526)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2017-9526)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2017-9526)

### Related Ubuntu Security Notices (USN)

+ [USN-3347-1](https://usn.ubuntu.com/USN-3347-1)
+ Libgcrypt vulnerabilities
+ 3 July 2017

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2017-9526>