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.

Published: 2017-12-07 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2017-17458 is rated High Risk (77.4/100): CVSS Critical severity, with high exploitation likelihood (EPSS 17.25%, 95th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +11.24% over the last day, indicating growing attacker interest. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2017-17458

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-04 6.01% 17.25% +11.24%
2 2026-03-01 17.25% 6.01% -11.24%
3 2026-02-04 17.25%

Full EPSS history (42 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-17458

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.0 CRITICAL
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 5.9 [email protected]
10.0 2.0 HIGH
AV:N/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
10.0 10.0 [email protected]

Weakness enumeration for CVE-2017-17458

GitHub Security Advisory for CVE-2017-17458

GHSA-6v56-cpg6-3rpx · Severity: critical · Ecosystem: pip — Mercurial vulnerable to arbitrary code injection

OS Trackers for CVE-2017-17458

vendor priority summary link
debian not yet assigned CVE-2017-17458 not yet assigned priority: Debian including 1 source packages (mercurial), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2017-17458
redhat medium https://access.redhat.com/security/cve/CVE-2017-17458
suse medium CVE-2017-17458 severity moderate: SUSE including 13 source package names (mercurial, mercurial-2.3.2-0.18.6.1, …), 29 product×package rows across 26 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 6, … (26 product lines)): Fixed 15, Known Not Affected 14. https://www.suse.com/security/cve/CVE-2017-17458/
ubuntu medium CVE-2017-17458 medium priority: Ubuntu including 1 source packages (mercurial), 7 status rows across 7 suites (artful, bionic, cosmic, trusty, upstream, xenial, zesty): released 3, ignored 2, not-affected 2. https://ubuntu.com/security/CVE-2017-17458

Affected software / configurations for CVE-2017-17458

Vendor Product Version Raw CPE
mercurial mercurial < 4.4.1 cpe:2.3:a:mercurial:mercurial:*:*:*:*:*:*:*:*
debian debian_linux 7.0 cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*

References for CVE-2017-17458

URL Tags
http://www.securityfocus.com/bid/102926 Third Party Advisory VDB Entry
https://bz.mercurial-scm.org/show_bug.cgi?id=5730 Issue Tracking Third Party Advisory
https://confluence.atlassian.com/sourcetreekb/sourcetree-security-advisory-2018-01-24-942834324.html Third Party Advisory
https://lists.debian.org/debian-lts-announce/2017/12/msg00027.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2018/07/msg00005.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2018/07/msg00041.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/07/msg00032.html
https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-November/107333.html Vendor Advisory
https://www.mercurial-scm.org/wiki/WhatsNew#Mercurial_4.4.1_.282017-11-07.29 Vendor Advisory
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