{"id":"CVE-2026-45287","aliases":["GHSA-995v-fvrw-c78m","GO-2026-5281"],"url":"https://o3.security/vulnerability/CVE-2026-45287","summary":"OpenTelemetry-Go's Schema ParseFile leaks file descriptors on each parse","details":"### Summary\n\n`go.opentelemetry.io/otel/schema/v1.0` and `go.opentelemetry.io/otel/schema/v1.1` leaks one file descriptor on each successful `ParseFile` call. `ParseFile` opens the schema file and passes it to `Parse` without closing it; repeated parsing in a long-running process can exhaust the process file descriptor limit and cause denial of service. The severity is low because exploitation depends on a consuming application exposing repeated schema parsing to an attacker-controlled path.\n\nIntroduced in commit: e72a235\n\n### Details\n\nIn `schema/v1.0/parser.go:41-47`, `ParseFile` opens the requested schema path with `os.Open` and then returns `Parse(file)` without a `defer file.Close()` or other close path:\n\n```go\nfile, err := os.Open(schemaFilePath)\nif err != nil {\n\treturn nil, err\n}\nreturn Parse(file)\n```\n\nThe validation evidence also identifies `schema/v1.0/parser.go:50-73`: `Parse` accepts an `io.Reader`, decodes from it, and does not close it. Ownership of the opened file is therefore not transferred to `Parse`, leaving the descriptor open until the Go runtime eventually finalizes the file object. With repeated `ParseFile` calls, descriptors can accumulate until the process receives `EMFILE` / \"too many open files\".\n\n### PoC\n\n[validation-artifact.zip](https://github.com/user-attachments/files/27494463/validation-artifact.zip)\n\nThe local artifact `validation-artifact.zip` contains:\n\n- `leak_poc.go`: PoC source that repeatedly calls `schema.ParseFile(\"schema/v1.0/testdata/valid-example.yaml\")` and prints `/proc/self/fd` counts.\n- `LEAK_POC_README.txt`: reproduction notes.\n- `leak_poc_run.log`: captured attempted run; the local offline environment failed before execution because Go module download from `proxy.golang.org` was forbidden.\n\nReproduce from the root of a checkout of `pellared/opentelemetry-go` at commit `e72a235` with Go module dependencies already available:\n\n```sh\n/bin/sh -c 'ulimit -n 256; GOGC=off go run leak_poc.go'\n```\n\nConfiguration:\n\n- File descriptor soft limit: `256`\n- Garbage collection: disabled with `GOGC=off` so leaked descriptors are not reclaimed during the loop\n- Schema file: `schema/v1.0/testdata/valid-example.yaml`\n\nExpected output is increasing descriptor counts followed by an `EMFILE` failure, for example:\n\n```text\niter 0 fds 7\niter 50 fds 57\niter 100 fds 107\n...\npanic: iteration 248: open schema/v1.0/testdata/valid-example.yaml: too many open files\n```\n\nThe exact initial descriptor count and failing iteration can vary by OS and process state.\n\n### Impact\n\nThis is a file descriptor resource leak leading to availability loss. Applications that call `schema.ParseFile` repeatedly, especially through a runtime reload or request-controlled path, can exhaust their process file descriptor table and fail subsequent file, socket, or other descriptor operations. Impact is limited to denial of service of the consuming process; the evidence does not show confidentiality or integrity impact.","published":"2026-06-04T14:45:54.522Z","modified":"2026-08-12T03:51:09.230033078Z","cvss":null,"epss":{"score":0.00168,"percentile":0.06457,"asOf":"2026-08-15"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"go.opentelemetry.io/otel/schema/v1.1","fixedVersion":"0.0.17"},{"ecosystem":"Go","name":"go.opentelemetry.io/otel/schema/v1.0","fixedVersion":"0.0.17"},{"ecosystem":"Go","name":"go.opentelemetry.io/otel/schema","fixedVersion":"0.0.17"}],"fix":{"url":"https://github.com/open-telemetry/opentelemetry-go/commit/e72a235518cb773137efd80336a179028bc34684","label":"open-telemetry/opentelemetry-go@e72a235"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45287.json"},{"type":"ADVISORY","url":"https://github.com/open-telemetry/opentelemetry-go/security/advisories/GHSA-995v-fvrw-c78m"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45287"},{"type":"FIX","url":"https://github.com/open-telemetry/opentelemetry-go/commit/e72a235518cb773137efd80336a179028bc34684"},{"type":"FIX","url":"https://github.com/open-telemetry/opentelemetry-go/commit/f12d198f161b61735d65705248715aa97021ba8d"},{"type":"PACKAGE","url":"https://github.com/open-telemetry/opentelemetry-go"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:09.230033078Z"}}