Uncaught Exception Affecting ddtrace package, versions [3.13.0,4.15.5)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PYTHON-DDTRACE-21756794
- published27 Oct 2026
- disclosed27 Oct 2026
- creditUnknown
Introduced: 27 Oct 2026
NewCVE-2026-116589 (opens in a new tab)How to fix?
Upgrade ddtrace to version 4.15.5 or higher.
Overview
ddtrace is a Datadog APM client library
Affected versions of this package are vulnerable to Uncaught Exception via modulo_aspect in the IAST taint-tracking C++ extension, when a lone surrogate character is passed as a format argument to the % (modulo) string operator. The unhandled surrogate causes a process abort, crashing the entire Python process.
Note: This is only exploitable if the IAST feature is explicitly enabled, as it is disabled by default.
PoC
Detailed triggering inputs and reproduction steps are omitted from this advisory. The linked fix (#20786) includes regression coverage for the affected behavior.
Note: The source PoC section states no specific environment, runtime version, or operating system.