CyberSecBulletin
CVE-2026-21575NVD status: Analyzed

Sourcetree for Mac: Improper Control of Generation of Code

CVE-2026-21575 is a high-severity improper control of generation of code vulnerability in Sourcetree for Mac from Atlassian, with a CVSS 3.1 base score of 8.0 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. Affected Sourcetree for Mac versions: All versions from 3.4.11 to 3.4.12 inclusive. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.59% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Sourcetree to 3.4.13 or a later version.
  2. Read the advisory on confluence.atlassian.com for workarounds and exact fixed builds.
  3. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
AtlassianSourcetree for MacAll versions from 3.4.11 to 3.4.12 inclusiveNot stated
AtlassianSourcetree3.4.11 up to, but not including, 3.4.133.4.13

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.0HighNVD
CVSS 3.07.1HighCNA (atlassian.com)

Official description

This High severity RCE (Remote Code Execution) vulnerability was introduced in version 3.4.11 of Sourcetree for Mac and Sourcetree for Windows. This RCE (Remote Code Execution) vulnerability, with a CVSS Score of 7.1, allows an authenticated attacker to execute arbitrary code which has high impact to confidentiality, high impact to integrity, high impact to availability, and requires user interaction. Atlassian recommends that Sourcetree for Mac and Sourcetree for Windows customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions: * Sourcetree for Mac and Sourcetree for Windows 3.4: Upgrade to a release greater than or equal to 3.4.13 See the release notes (https://www.sourcetreeapp.com/download-archives). You can download the latest version of Sourcetree for Mac and Sourcetree for Windows from the download center (https://www.sourcetreeapp.com/download-archives). This vulnerability was reported via our Bug Bounty program.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Control of Generation of Code

The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

How developers prevent this class of flaw

  • Refactor your program so that you do not have to dynamically generate code.
  • Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
  • Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.

More Improper Control of Generation of Code vulnerabilities (CWE-94)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other references

Other vulnerabilities in Sourcetree for Mac

All Sourcetree for Mac vulnerabilities

Recent Improper Control of Generation of Code vulnerabilities

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