What’s Vulnerable › Vulnerabilities

CVE-2026-116588: Datadog dd-trace-py: ReDOS in URL query string obfuscation

• Severity: high (CVSS 8.7 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-26 · updated 2026-10-27
• Weakness: CWE-1333

Description

Datadog dd-trace-py is the Datadog Python APM client. From 1.5.0 until 3.19.9 and 4.15.6, the default query-string obfuscation regular expression can exhibit excessive backtracking while synchronously processing attacker-controlled URL query strings for HTTP span metadata. A remote attacker can cause prolonged CPU consumption, request latency, and service unavailability in affected HTTP tracing integrations that include query strings in URL span tags. The vulnerable processing is enabled by default for those integrations. This issue is fixed in versions 3.19.9 and 4.15.6.

Affected products

• DataDog dd-trace-py: from 1.5.0, < 3.19.9; from 4.0.0, < 4.15.6

References

• https://github.com/DataDog/dd-trace-py/commit/63ddc3cb07d8813ded7a8b3ab5b8d0f5470e4bfd
• https://github.com/DataDog/dd-trace-py/commit/83ea39845dd95bfb9b8e247c62b3d22fc5dce1ce
• https://github.com/DataDog/dd-trace-py/commit/a6d73607ea45ecd67152630f64b0945556972ed8
• https://github.com/DataDog/dd-trace-py/pull/20857
• https://github.com/DataDog/dd-trace-py/pull/20862
• https://github.com/DataDog/dd-trace-py/pull/20880
• https://github.com/DataDog/dd-trace-py/releases/tag/v3.19.9
• https://github.com/DataDog/dd-trace-py/releases/tag/v4.15.6
• https://github.com/DataDog/dd-trace-py/security/advisories/GHSA-3633-r77q-h3v3

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