Summary
opentelemetry-go's Schema ParseFile leaks file descriptors on each parse
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.
Introduced in commit: e72a235
Details
In 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:
file, err := os.Open(schemaFilePath)
if err != nil {
return nil, err
}
return Parse(file)
The 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".
PoC
The local artifact validation-artifact.zip contains:
leak_poc.go: PoC source that repeatedly callsschema.ParseFile("schema/v1.0/testdata/valid-example.yaml")and prints/proc/self/fdcounts.LEAK_POC_README.txt: reproduction notes.leak_poc_run.log: captured attempted run; the local offline environment failed before execution because Go module download fromproxy.golang.orgwas forbidden.
Reproduce from the root of a checkout of pellared/opentelemetry-go at commit e72a235 with Go module dependencies already available:
/bin/sh -c 'ulimit -n 256; GOGC=off go run leak_poc.go'
Configuration:
- File descriptor soft limit:
256 - Garbage collection: disabled with
GOGC=offso leaked descriptors are not reclaimed during the loop - Schema file:
schema/v1.0/testdata/valid-example.yaml
Expected output is increasing descriptor counts followed by an EMFILE failure, for example:
iter 0 fds 7
iter 50 fds 57
iter 100 fds 107
...
panic: iteration 248: open schema/v1.0/testdata/valid-example.yaml: too many open files
The exact initial descriptor count and failing iteration can vary by OS and process state.
Impact
This 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.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
go.opentelemetry.io/otel/schema/v1.1 to 0.0.17 or later; go.opentelemetry.io/otel/schema/v1.0 to 0.0.17 or later; go.opentelemetry.io/otel/schema to 0.0.17 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-45287? CVE-2026-45287 is a low-severity security vulnerability in go.opentelemetry.io/otel/schema/v1.1 (go), affecting versions <= 0.0.16. It is fixed in 0.0.17.
- Which packages are affected by CVE-2026-45287?
go.opentelemetry.io/otel/schema/v1.1(go) (versions <= 0.0.16)go.opentelemetry.io/otel/schema/v1.0(go) (versions <= 0.0.16)go.opentelemetry.io/otel/schema(go) (versions < 0.0.17)
- Is there a fix for CVE-2026-45287? Yes. CVE-2026-45287 is fixed in 0.0.17. Upgrade to this version or later.
- Is CVE-2026-45287 exploitable, and should I be worried? Whether CVE-2026-45287 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-45287 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-45287?
- Upgrade
go.opentelemetry.io/otel/schema/v1.1to 0.0.17 or later - Upgrade
go.opentelemetry.io/otel/schema/v1.0to 0.0.17 or later - Upgrade
go.opentelemetry.io/otel/schemato 0.0.17 or later
- Upgrade