FedoraOperating system · Fedoraproject
CVE-2016-3630
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedThe 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe binary delta decoder in Mercurial versions before 3.7.3 contains a memory corruption vulnerability caused by a list sizing rounding error and improper handling of short records. This allows remote attackers to achieve arbitrary code execution via malicious Mercurial repositories during clone, push, or pull operations.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
FedoraOperating system
= 22= 23
Debian LinuxOperating system
= 7.0= 8.0= 42.1<= 3.7.2= 11= 13.2= 11= 12CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Verify Mercurial is installedRun 'hg --version' or check package manager (rpm -q mercurial, dpkg -l mercurial, zypper se mercurial)Affected if Mercurial is not installed or the command fails - not applicable to this system
-
Determine installed Mercurial versionExecute 'hg --version' and parse the version number from the output, or use package manager query (rpm -q --qf '%{VERSION}' mercurial, dpkg -s mercurial, zypper se -s mercurial)Affected if The version number returned is 3.7.2 or lower, or the version cannot be determined (may indicate older unpatched build)
-
Confirm binary delta decoder is in useThis feature is automatically used by Mercurial during clone, pull, or push operations. No explicit configuration check needed - the decoder is part of the core wire protocol.Affected if The system has performed or accepts remote repository operations (clone, pull, push) - vulnerability is reachable via these paths
If Mercurial is installed and the version is 3.7.2 or lower, the binary delta decoder is vulnerable to memory corruption during repository operations with untrusted sources.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpgrade Mercurial to version 3.7.3 or later to obtain the patched binary delta decoder. In interim, restrict repository access to trusted sources and apply network segmentation where possible.
Fix this in Fedora
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-3630 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2016-3630 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data