{"id":"CVE-2026-59892","aliases":["GHSA-45rx-2jwx-cxfr"],"url":"https://o3.security/vulnerability/CVE-2026-59892","summary":"OpenTelemetry JavaScript: Denial of service in `JaegerPropagator` via unhandled exception on a malformed header","details":"## Summary\n\n`@opentelemetry/propagator-jaeger` decodes incoming HTTP header values with `decodeURIComponent()` without handling decode errors. A single request carrying a malformed percent-encoded value (for example a bare `%`) in an `uber-trace-id` or `uberctx-*` header throws an uncaught `URIError`, terminating any Node.js process that uses `JaegerPropagator` as its active propagator.\n\n\n## Impact\n\n**Denial of Service:** Any unauthenticated remote attacker who can send an HTTP request to a service that has `JaegerPropagator` registered as the global propagator (e.g. via `OTEL_PROPAGATORS=jaeger` or `propagation.setGlobalPropagator(new JaegerPropagator())`) can terminate the process with a single request. Confidentiality and integrity are not affected.\n\n## Am I affected?\n\nThis issue affects only a specific, opt-in configuration. If you use OpenTelemetry's default propagators (W3C TraceContext and Baggage), you are **not** affected.          \n\nYou are affected only if you have registered `JaegerPropagator` as the active propagator. Check for:\n\n- `@opentelemetry/propagator-jaeger` in your dependency tree, **and**\n- `OTEL_PROPAGATORS` set to `jaeger` (Jaeger only), **or** a direct `propagation.setGlobalPropagator(new JaegerPropagator())` call in your code.\n\nNote: if `JaegerPropagator` is combined with other propagators through a `CompositePropagator` (for example `OTEL_PROPAGATORS=jaeger,tracecontext`), the process does not terminate - the composite propagator catches the error - but affected requests silently fail to extract context. You should still upgrade.\n\n\n## Patched versions\n\n- `@opentelemetry/propagator-jaeger` 2.9.0\n\n## Remediation\n\nUpdate `@opentelemetry/propagator-jaeger` to 2.9.0 or later. The propagator now ignores header values it cannot decode instead of throwing.\n\n**Interim mitigation (if you cannot update):** Trace-context headers should never be accepted unfiltered from untrusted callers. Until you can upgrade, strip or validate the `uber-trace-id` and `uberctx-*` headers on inbound requests at your edge - for example with a reverse proxy, API gateway, or load balancer (nginx, Envoy, etc.) - so that only trusted upstream services can set them.\n\n## Details\n\n`JaegerPropagator.extract()` calls `decodeURIComponent()` on raw header values at two unguarded call sites: the `uber-trace-id` trace header and each `uberctx-*` baggage value. `decodeURIComponent()` throws `URIError: URI malformed` on invalid percent-encoding. Because the HTTP instrumentation extracts context before its request-handler error wrapper, and a single configured propagator is not wrapped in a `CompositePropagator` (which would otherwise catch the error), the exception propagates as an `uncaughtException` and terminates the process.\n\n## Proof of concept\n\nAgainst a service using `JaegerPropagator`:\n\n```bash\ncurl -H 'uberctx-user: %' http://target/\n# or\ncurl -H 'uber-trace-id: %' http://target/\n```\n\nThe Node.js process exits with `URIError: URI malformed` and subsequent requests are refused.","published":"2026-07-08T16:03:58.439Z","modified":"2026-08-12T03:51:20.901249199Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.00784,"percentile":0.54285,"asOf":"2026-09-16"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"@opentelemetry/propagator-jaeger","fixedVersion":"2.9.0"}],"fix":{"url":"https://github.com/open-telemetry/opentelemetry-js/commit/b1c196d49d54caae59741cca0a9d57d101d7ea88","label":"open-telemetry/opentelemetry-js@b1c196d"},"references":[{"type":"WEB","url":"https://github.com/open-telemetry/opentelemetry-js/releases/tag/v2.9.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59892.json"},{"type":"ADVISORY","url":"https://github.com/open-telemetry/opentelemetry-js/security/advisories/GHSA-45rx-2jwx-cxfr"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59892"},{"type":"FIX","url":"https://github.com/open-telemetry/opentelemetry-js/commit/b1c196d49d54caae59741cca0a9d57d101d7ea88"},{"type":"PACKAGE","url":"https://github.com/open-telemetry/opentelemetry-js"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:20.901249199Z"}}