The binary delta decoder in Mercurial before 3.7.3 allows remote attackers to execute arbitrary code via a (1) clone, (2) push, or (3) pull
The binary delta decoder in Mercurial before 3.7.3 allows remote attackers to execute arbitrary code via a (1) clone, (2) push, or (3) pull command, related to (a) a list sizing rounding error and (b) short records.
- Published
- Apr 13, 2016
- Updated
- Jun 16, 2026
- EPSS
- 4.9% · 92th percentile
- CWE
- CWE-19
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Report tools
Action score
36
Monitor
Low priority for now.
- CVSS
- 35 / 40 · 8.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 4.9%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| mercurial | mercurial | cpe:2.3:a:mercurial:mercurial |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
| opensuse | leap | cpe:2.3:o:opensuse:leap |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
| suse | linux enterprise debuginfo | cpe:2.3:a:suse:linux_enterprise_debuginfo |
| opensuse | opensuse | cpe:2.3:o:opensuse:opensuse |
| suse | linux enterprise software development kit | cpe:2.3:o:suse:linux_enterprise_software_development_kit |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- debian debian linux7.0
- debian debian linux8.0
- fedoraproject fedora22
- fedoraproject fedora23
- mercurial mercurialup to 3.7.2 inclusive
- opensuse leap42.1
- opensuse opensuse13.2
- suse linux enterprise debuginfo11
- suse linux enterprise software development kit11
- suse linux enterprise software development kit12
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | mercurial | before 3.7.3-1 | 3.7.3-1 |
| Debian:7 | mercurial | before 2.2.2-4+deb7u2 | 2.2.2-4+deb7u2 |
| Debian:8 | mercurial | before 3.1.2-2+deb8u2 | 3.1.2-2+deb8u2 |
| openSUSE:Tumbleweed | mercurial | before 4.0-1.1 | 4.0-1.1 |
| PyPI | mercurial | before 3.7.3 | 3.7.3 |
| SUSE:Linux Enterprise Software Development Kit 11 SP4 | mercurial | before 2.3.2-0.11.1 | 2.3.2-0.11.1 |
| SUSE:Linux Enterprise Software Development Kit 12 | mercurial | before 2.8.2-6.1 | 2.8.2-6.1 |
Same product
mercurial: all recordsOther highest-scoring records for the same primary product.
- CVE-2014-9390Git before 1.8.5.6, 1.9.x before 1.9.5, 2.0.x before 2.0.5, 2.1.x before 2.1.4, and 2.2.x before 2.2.1 on Windows and OS X; Mercurial before62This week
- CVE-2017-9462In Mercurial before 4.1.3, "hg serve --stdio" allows remote authenticated users to launch the Python debugger, and consequently execute arbi42Plan
- CVE-2017-17458In Mercurial before 4.4.1, it is possible that a specially malformed repository can cause Git subrepositories to run arbitrary code in the f41Plan
- CVE-2017-1000116Mercurial prior to 4.3 did not adequately sanitize hostnames passed to ssh, leading to possible shell-injection attacks.41Plan
- CVE-2018-13347mpatch.c in Mercurial before 4.6.1 mishandles integer addition and subtraction, aka OVE-20180430-0002.40Plan
- CVE-2018-17983cext/manifest.c in Mercurial before 4.7.2 has an out-of-bounds read during parsing of a malformed manifest entry.37Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:mercurial | 3.7.3-1 · Debian:12 | Package registry (OSV) |
| opensuse:mercurial | 4.0-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| PyPI:mercurial | 3.7.3 | Package registry (OSV) |
| suse:mercurial | 2.8.2-6.1 · SUSE:Linux Enterprise Software Development Kit 12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-19 · Data Processing ErrorsCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
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References
- lists.fedoraproject.org/pipermail/package-announce/2016-April/181505.html
- lists.fedoraproject.org/pipermail/package-announce/2016-April/181542.html
- lists.opensuse.org/opensuse-security-announce/2016-04/msg00016.html
- lists.opensuse.org/opensuse-security-announce/2016-04/msg00017.html
- lists.opensuse.org/opensuse-security-announce/2016-04/msg00018.html
- lists.opensuse.org/opensuse-security-announce/2016-04/msg00043.html
- www.debian.org/security/2016/dsa-3542
- www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
- security.gentoo.org/glsa/201612-19
- selenic.com/repo/hg-stable/rev/b6ed2505d6cf
- selenic.com/repo/hg-stable/rev/b9714d958e89
- www.mercurial-scm.org/wiki/WhatsNew#Mercurial_3.7.3_.282016-3-29.29
Vendor advisories and official records. Exploit/PoC links are deliberately left out.