CVE-2017-9462

In Mercurial before 4.1.3, "hg serve --stdio" allows remote authenticated users to launch the Python debugger, and consequently execute arbitrary code, by using --debugger as a repository name.

Published: 2017-06-06 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2017-9462 is rated High Risk (67.3/100): CVSS High severity, with high exploitation likelihood (EPSS 48.70%, 98th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. 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-2017-9462

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 50.83% 48.70% -2.13%
2 2026-03-01 48.70% 50.83% +2.13%
3 2026-02-04 48.70%

Full EPSS history (53 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-9462

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/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:L)
A normal user session is enough; they don’t have to be admin.
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.
2.8 5.9 [email protected]
9.0 2.0 HIGH
AV:N/AC:L/Au:S/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:S)
A single authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
8.0 10.0 [email protected]

Weakness enumeration for CVE-2017-9462

GitHub Security Advisory for CVE-2017-9462

GHSA-ghjx-3jg5-h6r2 · Severity: high · Ecosystem: pip — Mercurial has Incorrect Permission Assignment for Critical Resource

OS Trackers for CVE-2017-9462

vendor priority summary link
debian not yet assigned CVE-2017-9462 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-2017-9462
gentoo normal CVE-2017-9462: 1 GLSA(s) (201709-18), 1 atom(s) (dev-vcs/mercurial); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2017-9462
redhat high https://access.redhat.com/security/cve/CVE-2017-9462
suse high CVE-2017-9462 severity important: SUSE including 7 source package names (emacs-mercurial-2.6.2-7.el7_3, emacs-mercurial-el-2.6.2-7.el7_3, …), 9 product×package rows across 6 product lines (SUSE Liberty Linux 7, SUSE Linux Enterprise Software Development Kit 11 SP4, … (6 product lines)): Fixed 9. https://www.suse.com/security/cve/CVE-2017-9462/
ubuntu medium CVE-2017-9462 medium priority: Ubuntu including 1 source packages (mercurial), 8 status rows across 8 suites (artful, bionic, cosmic, trusty, upstream, xenial, yakkety, zesty): released 3, ignored 2, not-affected 2, needs-triage 1. https://ubuntu.com/security/CVE-2017-9462

Affected software / configurations for CVE-2017-9462

Vendor Product Version Raw CPE
mercurial mercurial < 4.1.3 cpe:2.3:a:mercurial:mercurial:*:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 6.0 cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 7.0 cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_server 6.0 cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_server 7.0 cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 7.3 cpe:2.3:o:redhat:enterprise_linux_server_aus:7.3:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 7.4 cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 7.6 cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:*
redhat enterprise_linux_server_eus 7.3 cpe:2.3:o:redhat:enterprise_linux_server_eus:7.3:*:*:*:*:*:*:*
redhat enterprise_linux_server_eus 7.4 cpe:2.3:o:redhat:enterprise_linux_server_eus:7.4:*:*:*:*:*:*:*
redhat enterprise_linux_server_eus 7.5 cpe:2.3:o:redhat:enterprise_linux_server_eus:7.5:*:*:*:*:*:*:*
redhat enterprise_linux_server_eus 7.6 cpe:2.3:o:redhat:enterprise_linux_server_eus:7.6:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 7.3 cpe:2.3:o:redhat:enterprise_linux_server_tus:7.3:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 7.6 cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 6.0 cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 7.0 cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*

References for CVE-2017-9462

cvelogic Threat Intelligence