Vulnerability-Lookup

GHSA-W8RR-5GCM-PP58

Vulnerability from github – Published: 2026-04-08 19:22 – Updated: 2026-04-09 14:29

Summary

opentelemetry-go: OTLP HTTP exporters read unbounded HTTP response bodies

Details

overview: this report shows that 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).

severity

HIGH

not claiming: this is a remote dos against every default deployment. claiming: if the exporter sends traces to an untrusted collector endpoint (or over a network segment where mitm is realistic), that endpoint can crash the process via a large response body.

callsite (pinned): - exporters/otlp/otlptrace/otlptracehttp/client.go:199 - exporters/otlp/otlptrace/otlptracehttp/client.go:230 - exporters/otlp/otlpmetric/otlpmetrichttp/client.go:170 - exporters/otlp/otlpmetric/otlpmetrichttp/client.go:201 - exporters/otlp/otlplog/otlploghttp/client.go:190 - exporters/otlp/otlplog/otlploghttp/client.go:221

permalinks (pinned): - https://github.com/open-telemetry/opentelemetry-go/blob/248da958375e4dfb4a1105645107be3ef04b1c59/exporters/otlp/otlptrace/otlptracehttp/client.go#L199 - https://github.com/open-telemetry/opentelemetry-go/blob/248da958375e4dfb4a1105645107be3ef04b1c59/exporters/otlp/otlptrace/otlptracehttp/client.go#L230 - https://github.com/open-telemetry/opentelemetry-go/blob/248da958375e4dfb4a1105645107be3ef04b1c59/exporters/otlp/otlpmetric/otlpmetrichttp/client.go#L170 - https://github.com/open-telemetry/opentelemetry-go/blob/248da958375e4dfb4a1105645107be3ef04b1c59/exporters/otlp/otlpmetric/otlpmetrichttp/client.go#L201 - https://github.com/open-telemetry/opentelemetry-go/blob/248da958375e4dfb4a1105645107be3ef04b1c59/exporters/otlp/otlplog/otlploghttp/client.go#L190 - https://github.com/open-telemetry/opentelemetry-go/blob/248da958375e4dfb4a1105645107be3ef04b1c59/exporters/otlp/otlplog/otlploghttp/client.go#L221

root cause: each exporter client reads resp.Body using io.Copy(&respData, resp.Body) into a bytes.Buffer on both success and error paths, with no upper bound.

impact: a malicious collector can force large transient heap allocations during export (peak memory scales with attacker-chosen response size) and can potentially crash the instrumented process (oom).

affected component: - go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp - go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp - go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp

repro (local-only):

unzip poc.zip -d poc
cd poc
make canonical resp_bytes=33554432 chunk_delay_ms=0

expected output contains:

[CALLSITE_HIT]: otlptracehttp.UploadTraces::io.Copy(resp.Body)
[PROOF_MARKER]: resp_bytes=33554432 peak_alloc_bytes=118050512

control (same env, patched target):

unzip poc.zip -d poc
cd poc
make control resp_bytes=33554432 chunk_delay_ms=0

expected control output contains:

[CALLSITE_HIT]: otlptracehttp.UploadTraces::io.Copy(resp.Body)
[NC_MARKER]: resp_bytes=33554432 peak_alloc_bytes=512232

attachments: poc.zip (attached)

PR_DESCRIPTION.md

attack_scenario.md

poc.zip

Fixed in: https://github.com/open-telemetry/opentelemetry-go/pull/8108

Severity ?

5.3 (Medium)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.43.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.43.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.19.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-39882"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-789"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-08T19:22:01Z",
    "nvd_published_at": "2026-04-08T21:17:00Z",
    "severity": "MODERATE"
  },
  "details": "overview:\nthis report shows that the otlp HTTP exporters (traces/metrics/logs) read the full HTTP response body into an in-memory `bytes.Buffer` without a size cap.\n\nthis is exploitable for memory exhaustion when the configured collector endpoint is attacker-controlled (or a network attacker can mitm the exporter connection).\n\nseverity\n\nHIGH\n\nnot claiming: this is a remote dos against every default deployment.\nclaiming: if the exporter sends traces to an untrusted collector endpoint (or over a network segment where mitm is realistic), that endpoint can crash the process via a large response body.\n\ncallsite (pinned):\n- exporters/otlp/otlptrace/otlptracehttp/client.go:199\n- exporters/otlp/otlptrace/otlptracehttp/client.go:230\n- exporters/otlp/otlpmetric/otlpmetrichttp/client.go:170\n- exporters/otlp/otlpmetric/otlpmetrichttp/client.go:201\n- exporters/otlp/otlplog/otlploghttp/client.go:190\n- exporters/otlp/otlplog/otlploghttp/client.go:221\n\npermalinks (pinned):\n- https://github.com/open-telemetry/opentelemetry-go/blob/248da958375e4dfb4a1105645107be3ef04b1c59/exporters/otlp/otlptrace/otlptracehttp/client.go#L199\n- https://github.com/open-telemetry/opentelemetry-go/blob/248da958375e4dfb4a1105645107be3ef04b1c59/exporters/otlp/otlptrace/otlptracehttp/client.go#L230\n- https://github.com/open-telemetry/opentelemetry-go/blob/248da958375e4dfb4a1105645107be3ef04b1c59/exporters/otlp/otlpmetric/otlpmetrichttp/client.go#L170\n- https://github.com/open-telemetry/opentelemetry-go/blob/248da958375e4dfb4a1105645107be3ef04b1c59/exporters/otlp/otlpmetric/otlpmetrichttp/client.go#L201\n- https://github.com/open-telemetry/opentelemetry-go/blob/248da958375e4dfb4a1105645107be3ef04b1c59/exporters/otlp/otlplog/otlploghttp/client.go#L190\n- https://github.com/open-telemetry/opentelemetry-go/blob/248da958375e4dfb4a1105645107be3ef04b1c59/exporters/otlp/otlplog/otlploghttp/client.go#L221\n\nroot cause:\neach exporter client reads `resp.Body` using `io.Copy(\u0026respData, resp.Body)` into a `bytes.Buffer` on both success and error paths, with no upper bound.\n\nimpact:\na malicious collector can force large transient heap allocations during export (peak memory scales with attacker-chosen response size) and can potentially crash the instrumented process (oom).\n\naffected component:\n- go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp\n- go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp\n- go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp\n\nrepro (local-only):\n\n```bash\nunzip poc.zip -d poc\ncd poc\nmake canonical resp_bytes=33554432 chunk_delay_ms=0\n```\n\nexpected output contains:\n\n```\n[CALLSITE_HIT]: otlptracehttp.UploadTraces::io.Copy(resp.Body)\n[PROOF_MARKER]: resp_bytes=33554432 peak_alloc_bytes=118050512\n```\n\ncontrol (same env, patched target):\n\n```bash\nunzip poc.zip -d poc\ncd poc\nmake control resp_bytes=33554432 chunk_delay_ms=0\n```\n\nexpected control output contains:\n\n```\n[CALLSITE_HIT]: otlptracehttp.UploadTraces::io.Copy(resp.Body)\n[NC_MARKER]: resp_bytes=33554432 peak_alloc_bytes=512232\n```\n\nattachments: poc.zip (attached)\n\n[PR_DESCRIPTION.md](https://github.com/user-attachments/files/25564272/PR_DESCRIPTION.md)\n\n[attack_scenario.md](https://github.com/user-attachments/files/25564273/attack_scenario.md)\n\n[poc.zip](https://github.com/user-attachments/files/25564271/poc.zip)\n\n\nFixed in: https://github.com/open-telemetry/opentelemetry-go/pull/8108",
  "id": "GHSA-w8rr-5gcm-pp58",
  "modified": "2026-04-09T14:29:37Z",
  "published": "2026-04-08T19:22:01Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/open-telemetry/opentelemetry-go/security/advisories/GHSA-w8rr-5gcm-pp58"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-39882"
    },
    {
      "type": "WEB",
      "url": "https://github.com/open-telemetry/opentelemetry-go/pull/8108"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/open-telemetry/opentelemetry-go"
    },
    {
      "type": "WEB",
      "url": "http://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.43.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "opentelemetry-go: OTLP HTTP exporters read unbounded HTTP response bodies"
}

CVE-2026-39882 (GCVE-0-2026-39882)

Vulnerability from cvelistv5 – Published: 2026-04-08 20:24 – Updated: 2026-04-09 20:22

Title

OpenTelemetry-Go OTLP HTTP exporters read unbounded HTTP response bodies

Summary

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.

Severity ?

5.3 (Medium)


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

CWE

CWE-789 - Memory Allocation with Excessive Size Value

Assigner

GitHub_M

References

URL

Tags

	https://github.com/open-telemetry/opentelemetry-g…	x_refsource_CONFIRM
	https://github.com/open-telemetry/opentelemetry-g…	x_refsource_MISC

Impacted products

	Vendor	Product	Version
	open-telemetry	opentelemetry-go	Affected: < 1.43.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-39882",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-09T20:21:49.122499Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-09T20:22:03.109Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "opentelemetry-go",
          "vendor": "open-telemetry",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.43.0"
            }
          ]
        }
      ],
      "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": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "ADJACENT_NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-789",
              "description": "CWE-789: Memory Allocation with Excessive Size Value",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-08T20:24:19.246Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/open-telemetry/opentelemetry-go/security/advisories/GHSA-w8rr-5gcm-pp58",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/open-telemetry/opentelemetry-go/security/advisories/GHSA-w8rr-5gcm-pp58"
        },
        {
          "name": "https://github.com/open-telemetry/opentelemetry-go/pull/8108",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/open-telemetry/opentelemetry-go/pull/8108"
        }
      ],
      "source": {
        "advisory": "GHSA-w8rr-5gcm-pp58",
        "discovery": "UNKNOWN"
      },
      "title": "OpenTelemetry-Go OTLP HTTP exporters read unbounded HTTP response bodies"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-39882",
    "datePublished": "2026-04-08T20:24:19.246Z",
    "dateReserved": "2026-04-07T20:32:03.010Z",
    "dateUpdated": "2026-04-09T20:22:03.109Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-W8RR-5GCM-PP58

CVE-2026-39882 (GCVE-0-2026-39882)

Tags

Sightings

Nomenclature