Summary
Datadog dd-trace-py: IAST instrumentation can lead to application DOS
A flaw in dd-trace-py’s IAST instrumentation can cause the Python application process to terminate unexpectedly when processing certain attacker-controlled input. Only applications with IAST enabled are affected. IAST is disabled by default.
Details
The affected IAST string-processing instrumentation does not properly handle certain internal errors, allowing an error to terminate the application process. Exploitation requires IAST to be enabled and application code to perform an affected string-processing operation on attacker-controlled input.
If you are unable to upgrade to a patched version of dd-trace-py, you can mitigate this issue by either disabling IAST (setting DD_IAST_ENABLED=false) or by replacing replace % string interpolations with str.format or f-strings for user inputs in your monitored application.
Proof of concept
Detailed triggering inputs and reproduction steps are omitted from this advisory. The linked fix (#20786) includes regression coverage for the affected behavior.
Impact
Denial of service affecting applications that use a vulnerable version of dd-trace-py with IAST enabled and expose the affected operation to attacker-controlled input. Successful exploitation terminates the affected Python process and interrupts the work it is handling.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-116589? CVE-2026-116589 is a high-severity security vulnerability in ddtrace (pip), affecting versions >= 3.13.0, < 4.15.5. It is fixed in 4.15.5.
- Which versions of ddtrace are affected by CVE-2026-116589? ddtrace (pip) versions >= 3.13.0, < 4.15.5 is affected.
- Is there a fix for CVE-2026-116589? Yes. CVE-2026-116589 is fixed in 4.15.5. Upgrade to this version or later.
- Is CVE-2026-116589 exploitable, and should I be worried? Whether CVE-2026-116589 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-116589 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-116589? Upgrade
ddtraceto 4.15.5 or later.