CVE-2019-3902

Publication date 22 April 2019

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

A flaw was found in Mercurial before 4.9. It was possible to use symlinks and subrepositories to defeat Mercurial's path-checking logic and write files outside a repository.

From the Ubuntu Security Team

It was discovered that Mercurial mishandled symlinks in subrepositories. An attacker could use this vulnerability to write arbitrary files to the target's filesystem.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
mercurial	22.04 LTS jammy	Not affected
	21.10 impish	Not affected
	21.04 hirsute	Not affected
	20.10 groovy	Not affected
	20.04 LTS focal	Not affected
	19.10 eoan	Not affected
	19.04 disco	Fixed 4.8.2-1ubuntu3.19.04.1
	18.10 cosmic	Ignored end of life
	18.04 LTS bionic	Fixed 4.5.3-1ubuntu2.2
	16.04 LTS xenial	Fixed 3.7.3-1ubuntu1.2+esm2
	14.04 LTS trusty	Fixed 2.8.2-1ubuntu1.4+esm1

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Severity score breakdown

Parameter	Value
Base score	5.9 · Medium
Attack vector	Network
Attack complexity	High
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	High
Availability impact	None
Vector	CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

References

Related Ubuntu Security Notices (USN)

USN-4086-1
Mercurial vulnerability
6 August 2019

USN-5102-1
Mercurial vulnerabilities
4 October 2021

USN-5102-2
Mercurial vulnerabilities
16 March 2021