CVE-2026-9270 Overview
CVE-2026-9270 is a metric injection vulnerability in the DataDog::DogStatsd Perl module through version 0.07. The module fails to sanitize input passed to the send_stats method, allowing attackers to inject arbitrary metrics through unvalidated metric names, values, and tags. Newline characters in the $stat variable allow attackers to alter the metric name prefix. The $delta variable accepts unrestricted values across set, gauge, count, and histogram methods. Tag inputs accept newlines, pipes, and colons, all of which break out of the intended metric format. The module's own SYNOPSIS demonstrates an unsafe pattern by passing a web form loginName parameter directly as a tag.
Critical Impact
Attackers passing untrusted input to DogStatsd methods can inject arbitrary metrics, poison telemetry data, and corrupt monitoring pipelines.
Affected Products
- DataDog::DogStatsd for Perl, versions through 0.07
- Perl applications consuming the affected CPAN module
- Monitoring pipelines ingesting metrics from vulnerable producers
Discovery Timeline
- 2026-06-05 - CVE-2026-9270 published to NVD
- 2026-06-10 - Last updated in NVD database
Technical Details for CVE-2026-9270
Vulnerability Analysis
The vulnerability is classified as Improper Neutralization of CRLF Sequences [CWE-93]. The send_stats method in DataDog::DogStatsd constructs StatsD wire-protocol messages by concatenating user-supplied values without sanitization. The StatsD protocol uses newlines as message separators, pipes as field separators, and colons to separate metric names from values. Any of these characters embedded in attacker-controlled input break out of the intended metric and create injected metrics.
Three distinct injection vectors exist in the same method. The $stat parameter accepts newlines, allowing prefix manipulation and injection of fully formed secondary metrics. The $delta parameter accepts arbitrary content across multiple metric types because set, gauge, count, and histogram do not enforce numeric typing. The tag parameter accepts newlines, pipes, and colons, allowing both metric forgery and tag forgery against downstream consumers.
Root Cause
The root cause is the absence of output encoding for StatsD protocol delimiters. The module trusts callers to provide pre-sanitized values rather than enforcing protocol-safe encoding at the serialization boundary. The published SYNOPSIS reinforces this anti-pattern by showing user-controlled form fields used directly as tag values.
Attack Vector
Attackers supply crafted strings to any application path that forwards user input into DogStatsd calls. A login form passing loginName as a tag, as shown in the module's own example, is sufficient. An attacker submits a value containing \n, |, or : characters to inject additional metrics into the Datadog agent. Injected metrics can poison dashboards, trigger or suppress alerts, inflate billing on metered ingestion, and corrupt anomaly detection baselines.
No verified public exploit code is available. See the related advisories CVE-2026-46719, CVE-2026-46720, and CVE-2026-46741 for context on related injection issues.
Detection Methods for CVE-2026-9270
Indicators of Compromise
- StatsD UDP or TCP payloads containing embedded newline (\n), pipe (|), or colon (:) characters in unexpected positions
- Unexpected metric names appearing in Datadog dashboards that do not correspond to instrumented code paths
- Sudden spikes in metric cardinality or tag cardinality tied to user-input fields such as loginName
- Application logs showing user input containing CRLF sequences forwarded to monitoring code paths
Detection Strategies
- Inspect outbound StatsD traffic at the agent ingress and flag payloads containing protocol delimiters inside name or value fields
- Audit Perl source for calls to send_stats, increment, decrement, gauge, histogram, set, and count and trace argument provenance back to request handlers
- Compare the active metric namespace against an allow-list of expected metric names and alert on deviations
Monitoring Recommendations
- Enable verbose logging on the Datadog Agent to capture malformed or unexpected metric submissions
- Track tag cardinality growth and alert when a single tag key exceeds expected unique-value thresholds
- Correlate web application access logs containing suspicious characters with metric submission timestamps
How to Mitigate CVE-2026-9270
Immediate Actions Required
- Inventory all Perl services that depend on DataDog::DogStatsd and identify those passing user-controlled input into metric names, values, or tags
- Apply input validation at the application layer, rejecting or stripping newlines, pipes, and colons before any DogStatsd call
- Restrict $delta arguments to numeric types using explicit looks_like_number checks prior to submission
- Remove the unsafe loginName-as-tag pattern from any code derived from the module SYNOPSIS
Patch Information
At the time of publication, no fixed version of DataDog::DogStatsd is referenced in the NVD record. Monitor CPAN and the module's distribution channel for an updated release that enforces sanitization in send_stats. Until a patched release is available, treat all callers as responsible for sanitization.
Workarounds
- Wrap DogStatsd calls in an application-side sanitizer that removes or rejects \r, \n, |, and : from all string arguments
- Enforce a strict allow-list of metric names and tag keys at the wrapper layer
- Drop user-controlled values from tag positions entirely and use server-generated identifiers instead
- Configure the Datadog Agent to ingest from a trusted local socket only, blocking direct attacker access to the StatsD listener
# Configuration example: restrict DogStatsd agent to localhost only
# /etc/datadog-agent/datadog.yaml
use_dogstatsd: true
dogstatsd_non_local_traffic: false
bind_host: 127.0.0.1
dogstatsd_port: 8125
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
