---
title: "CVE-2023-29409\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-2023-29409?format=md
keywords: index, follow
---

# CVE-2023-29409

Publication date 2 August 2023

Last updated 29 July 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**5.3 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2023-29409?format=md#impact-score)

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## Description

Extremely large RSA keys in certificate chains can cause a client/server to
expend significant CPU time verifying signatures. With fix, the size of RSA
keys transmitted during handshakes is restricted to <= 8192 bits. Based on
a survey of publicly trusted RSA keys, there are currently only three
certificates in circulation with keys larger than this, and all three
appear to be test certificates that are not actively deployed. It is
possible there are larger keys in use in private PKIs, but we target the
web PKI, so causing breakage here in the interests of increasing the
default safety of users of crypto/tls seems reasonable.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| golang-1.19 | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release |
| 25.04 plucky | Not in release |
| 24.10 oracular | Not in release |
| 24.04 LTS noble | Not in release |
| 23.10 mantic | Not in release |
| 23.04 lunar | Ignored end of life, was needs-triage |
| 22.04 LTS jammy | Not in release |
| 20.04 LTS focal | Not in release |
| 18.04 LTS bionic | Not in release |
| 16.04 LTS xenial | Not in release |
| 14.04 LTS trusty | Not in release |
| golang-1.20 | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release |
| 25.04 plucky | Not in release |
| 24.10 oracular | Not in release |
| 24.04 LTS noble | Not in release |
| 23.10 mantic | Ignored end of life, was needs-triage |
| 23.04 lunar | Ignored end of life, was needs-triage |
| 22.04 LTS jammy | Needs evaluation |
| 20.04 LTS focal | Needs evaluation |
| 18.04 LTS bionic | Not in release |
| 16.04 LTS xenial | Not in release |
| 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**

5.3 · Medium

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 5.3 · Medium |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-29409)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2023-29409)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2023-29409)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2023-29409)

### Other references

* <https://groups.google.com/g/golang-announce/c/X0b6CsSAaYI>
* <https://github.com/golang/go/issues/61460>
* <https://github.com/golang/go/commit/a51957fb0b20bb6c91d0415efca222cc9ecdb770(1.21)>
* <https://github.com/golang/go/commit/659f2a22076713bd2500adc82e026b6a746d8ba1(1.20)>
* <https://github.com/golang/go/commit/2300f7ef07718f6be4d8aa8486c7de99836e233f(1.19)>
* <https://www.cve.org/CVERecord?id=CVE-2023-29409>