dd-trace: ReDOS in URL query string obfuscation

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

dd-trace is the Datadog APM client for Node.js. From 2.0.0 until 5.131.1 and 6.20.1, the default DD_TRACE_OBFUSCATION_QUERY_STRING_REGEXP can perform excessive backtracking on attacker-controlled URL query strings. The expression is applied synchronously while recording HTTP URL metadata, allowing a crafted request to consume excessive CPU, stall request processing, and make the instrumented application unavailable. This issue is fixed in versions 5.131.1 and 6.20.1.

Source published

27 Oct 2026 20:07:01 UTC

Source modified

30 Oct 2026 19:25:57 UTC

Observed here

30 Oct 2026 22:45:26 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

dd-trace is the Datadog APM client for Node.js. From 2.0.0 until 5.131.1 and 6.20.1, the default DD_TRACE_OBFUSCATION_QUERY_STRING_REGEXP can perform excessive backtracking on attacker-controlled URL query strings. The expression is applied synchronously while recording HTTP URL metadata, allowing a crafted request to consume excessive CPU, stall request processing, and make the instrumented application unavailable. This issue is fixed in versions 5.131.1 and 6.20.1.

Source published

Oct 27, 2026, 8:07:01 PM (timezone not stated)

Source modified

Oct 27, 2026, 8:07:01 PM (timezone not stated)

Observed here

30 Oct 2026 02:00:20 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 4.0 · 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

dd-trace is the Datadog APM client for Node.js. From 2.0.0 until 5.131.1 and 6.20.1, the default DD_TRACE_OBFUSCATION_QUERY_STRING_REGEXP can perform excessive backtracking on attacker-controlled URL query strings. The expression is applied synchronously while recording HTTP URL metadata, allowing a crafted request to consume excessive CPU, stall request processing, and make the instrumented application unavailable. This issue is fixed in versions 5.131.1 and 6.20.1.

Source published

27 Oct 2026 21:18:05 UTC

Source modified

28 Oct 2026 15:24:56 UTC

Observed here

29 Oct 2026 21:50:49 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · [email protected] · Secondary · 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

### Summary A regular expression used to obfuscate URL query strings can consume excessive CPU when processing certain attacker-controlled input. This can stall request processing and cause denial of service in applications using affected HTTP tracing integrations. ### Details The default query-string obfuscation pattern can exhibit excessive backtracking. The pattern is applied synchronously when recording HTTP URL metadata, allowing query-string processing to occupy application resources for an extended period. As a workaround, set DD_TRACE_OBFUSCATION_QUERY_STRING_REGEXP to the fixed regex below, then restart the application. ``` DD_TRACE_OBFUSCATION_QUERY_STRING_REGEXP='(?:(?:"|%22)?)(?:(?:old[-_]?|new[-_]?)?p(?:ass)?w(?:or)?d(?:1|2)?|pass(?:[-_]?phrase)?|secret|(?:api[-_]?|private[-_]?|public[-_]?|access[-_]?|secret[-_]?|app(?:lication)?[-_]?)key(?:[-_]?id)?|token|consumer[-_]?(?:id|key|secret)|sign(?:ed|ature)?|auth(?:entication|orization)?)(?:(?:\s|%20)*(?:=|%3D)[^&]+|(?:"|%22)(?:\s|%20)*(?::|%3A)(?:\s|%20)*(?:"|%22)(?:%2[^2]|%[^2]|[^"%])+(?:"|%22))|(?:bearer(?:\s|%20)+[a-z0-9._\-]+|token(?::|%3A)[a-z0-9]{13}|gh[opsu]_[0-9a-zA-Z]{36}|(?:(?<![\w-])|(?<=%[0-9a-f]{2}))ey[I-L][\w-]+(?:=|%3D)*\.ey[I-L][\w-]+(?:=|%3D)*(?:\.(?:[\w.+/=-]|%3D|%2F|%2B)+)?|-{5}BEGIN(?:[a-z\s]|%20)+PRIVATE(?:\s|%20)KEY-{5}[^\-]+-{5}END(?:[a-z\s]|%20)+PRIVATE(?:\s|%20)KEY(?:-{5})?(?:\n|%0A)?|(?:ssh-(?:rsa|dss)|ecdsa-[a-z0-9]+-[a-z0-9]+)(?:\s|%20|%09)+(?:[a-z0-9/.+]|%2F|%5C|%2B){100,}(?:=|%3D)*(?:(?:\s|%20|%09)+[a-z0-9._-]+)?)' ``` ### Proof of concept Detailed triggering inputs and reproduction steps are omitted from this advisory. The patched version includes regression coverage for the affected behavior. ### Impact Regular expression denial of service (ReDoS) affecting applications that process attacker-controlled URL query strings through the vulnerable obfuscation pattern. Successful exploitation can cause excessive CPU consumption, prolonged request latency, and service unavailability. The vulnerable processing is enabled by default for affected HTTP integrations that include query strings in URL span tags.

Source published

27 Oct 2026 21:07:25 UTC

Source modified

27 Oct 2026 21:15:03 UTC

Observed here

27 Oct 2026 21:46:44 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Publisher rating · HIGH