{"id":"GHSA-995v-fvrw-c78m","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.","aliases":["CVE-2026-45287","GO-2026-5281"],"modified":"2026-07-15T22:00:55.919259184Z","published":"2026-05-28T17:19:10Z","database_specific":{"severity":"LOW","github_reviewed":true,"github_reviewed_at":"2026-05-28T17:19:10Z","nvd_published_at":"2026-06-04T16:16:38Z","cwe_ids":["CWE-772","CWE-775"]},"references":[{"type":"WEB","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":"WEB","url":"https://github.com/open-telemetry/opentelemetry-go/commit/e72a235518cb773137efd80336a179028bc34684"},{"type":"WEB","url":"https://github.com/open-telemetry/opentelemetry-go/commit/f12d198f161b61735d65705248715aa97021ba8d"},{"type":"PACKAGE","url":"https://github.com/open-telemetry/opentelemetry-go"}],"affected":[{"package":{"name":"go.opentelemetry.io/otel/schema/v1.1","ecosystem":"Go","purl":"pkg:golang/go.opentelemetry.io/otel/schema/v1.1"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.0.17"}]}],"database_specific":{"last_known_affected_version_range":"\u003c= 0.0.16","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-995v-fvrw-c78m/GHSA-995v-fvrw-c78m.json"}},{"package":{"name":"go.opentelemetry.io/otel/schema/v1.0","ecosystem":"Go","purl":"pkg:golang/go.opentelemetry.io/otel/schema/v1.0"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.0.17"}]}],"database_specific":{"last_known_affected_version_range":"\u003c= 0.0.16","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-995v-fvrw-c78m/GHSA-995v-fvrw-c78m.json"}},{"package":{"name":"go.opentelemetry.io/otel/schema","ecosystem":"Go","purl":"pkg:golang/go.opentelemetry.io/otel/schema"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.0.17"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-995v-fvrw-c78m/GHSA-995v-fvrw-c78m.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"}]}