# OpenTelemetry-Go: Unsynchronized baggage map can panic under concurrent access

Advisory record · `GHSA-42cj-99w8-cp2p`

- **Identifiers:** `GHSA-42cj-99w8-cp2p` · `CVE-2026-45404` · `GO-2026-6258`
- **State:** Confirmed
- **Severity:** CVSS 5.9 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-362](https://cwe.mitre.org/data/definitions/362.html) · [CWE-667](https://cwe.mitre.org/data/definitions/667.html)
- **Tags:** [Race condition](https://agentprime.io/advisories/tag/race-condition.md) · [CWE-667](https://agentprime.io/advisories/tag/cwe-667.md)
- **Published:** 20 Aug 2026
- **Updated:** 10 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 20 Aug 2026, 17:26 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `go.opentelemetry.io/otel/bridge/opentracing` (Go): affected `>=0.11.0, <1.45.0`; fixed in `1.45.0`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> The OpenTelemetry-Go OpenTracing bridge (go.opentelemetry.io/otel/bridge/opentracing) versions from 0.11.0 before 1.45.0 are affected. Concurrent calls to SetBaggageItem and correlation.MapFromContext on the same span can access an unsynchronized map, causing a fatal runtime panic that crashes the process. The attack requires a specific bridge configuration with correlation hooks and concurrent use of one span. Upgrade to version 1.45.0 or later.

Written 1 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 5.9 Medium, CVSS 4.0: `CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0014, the 3rd percentile, on 6 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:13 UTC: First seen by agentprime
- 31 Oct 2026, 14:13 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-42cj-99w8-cp2p)

## Sources

- [GitHub Advisory Database: GHSA-42cj-99w8-cp2p](https://github.com/advisories/GHSA-42cj-99w8-cp2p)
- [OSV: GHSA-42cj-99w8-cp2p](https://osv.dev/vulnerability/GHSA-42cj-99w8-cp2p)
- <https://github.com/open-telemetry/opentelemetry-go/security/advisories/GHSA-42cj-99w8-cp2p>
- <https://github.com/open-telemetry/opentelemetry-go/pull/8693>
- <https://github.com/open-telemetry/opentelemetry-go/commit/93a693edeed0e07ce5ebd1dfe67af42d1e2055d8>
- <https://github.com/open-telemetry/opentelemetry-go>
- <https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.45.0>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-42cj-99w8-cp2p>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-42cj-99w8-cp2p/>. Everything for agents: <https://agentprime.io/llms.txt>.