FedoraOperating system · Fedoraproject
CVE-2016-7952
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 · uneditedX.org libXtst before 1.2.3 allows remote X servers to cause a denial of service (infinite loop) via a reply in the (1) XRecordStartOfData, (2) XRecordEndOfData, or (3) XRecordClientDied category without a client sequence and with attached data.
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 confidenceX.org libXtst before version 1.2.3 contains an infinite loop vulnerability in the X Record extension. When processing replies for XRecordStartOfData, XRecordEndOfData, or XRecordClientDied categories, the library fails to properly handle replies that lack a client sequence but contain attached data, causing an infinite loop and denial of service.
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
= 24= 25<= 1.2.2CVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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.
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Check installed libXtst versionOn Fedora: rpm -q libXtst. On Debian/Ubuntu: dpkg -l libxtst. On general Linux: look for libXtst.so version in /usr/lib/ and compare to 1.2.2Affected if Version is 1.2.2 or lower, or the package is not at version 1.2.3
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Identify applications using X Record extensionRun 'ldd /path/to/application | grep -i xtst' on suspect applications, or check application documentation for X Record (XRECORD) usageAffected if Applications link against libXtst and use the X Record extension for data capture/recording
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Verify X Record is actively processing client dataCheck if applications are actively using XRecordStartOfData, XRecordEndOfData, or XRecordClientDied category ranges - inspect running processes or application logs for X Record API callsAffected if Applications are actively recording/monitoring X events using the vulnerable X Record categories
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Check for hung processes from X RecordMonitor for processes that have become unresponsive while performing X recording operations, which may indicate the infinite loop has been triggeredAffected if Processes using X Record have become unresponsive or are consuming 100% CPU during recording operations
You are affected if libXtst version is 1.2.2 or lower AND any application actively uses the X Record extension with the vulnerable categories (XRecordStartOfData, XRecordEndOfData, or XRecordClientDied).
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 dataUpdate libXtst to version 1.2.3 or later. On Linux systems, this typically involves updating the libxtst or similar package through the distribution's package manager.
Fix this in Fedora
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 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 $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-7952 — 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-2016-7952 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
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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