Debian Security Advisory

DLA-2293-1 mercurial -- LTS security update

Date Reported:
27 Jul 2020
Affected Packages:
Security database references:
In the Debian bugtracking system: Bug 901050, Bug 892964, Bug 927674.
In Mitre's CVE dictionary: CVE-2017-17458, CVE-2018-13346, CVE-2018-13347, CVE-2018-13348, CVE-2018-1000132, CVE-2019-3902.
More information:

Several vulnerabilities were discovered in mercurial, an easy-to-use, scalable distributed version control system.

  • CVE-2017-17458

    In Mercurial before 4.4.1, it is possible that a specially malformed repository can cause Git subrepositories to run arbitrary code in the form of a .git/hooks/post-update script checked into the repository. Typical use of Mercurial prevents construction of such repositories, but they can be created programmatically.

  • CVE-2018-13346

    The mpatch_apply function in mpatch.c in Mercurial before 4.6.1 incorrectly proceeds in cases where the fragment start is past the end of the original data.

  • CVE-2018-13347

    mpatch.c in Mercurial before 4.6.1 mishandles integer addition and subtraction.

  • CVE-2018-13348

    The mpatch_decode function in mpatch.c in Mercurial before 4.6.1 mishandles certain situations where there should be at least 12 bytes remaining after the current position in the patch data, but actually are not.

  • CVE-2018-1000132

    Mercurial version 4.5 and earlier contains a Incorrect Access Control (CWE-285) vulnerability in Protocol server that can result in Unauthorized data access. This attack appear to be exploitable via network connectivity. This vulnerability appears to have been fixed in 4.5.1.

  • CVE-2019-3902

    Symbolic links and subrepositories could be used defeat Mercurial's path-checking logic and write files outside the repository root.

For Debian 9 stretch, these problems have been fixed in version 4.0-1+deb9u2.

We recommend that you upgrade your mercurial packages.

For the detailed security status of mercurial please refer to its security tracker page at:

Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: