Vulnerability in golang (CVE-2026-39825)
Summary
Vulnerability in golang (CVE-2026-39825). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 1.25.10, 1.26.3 or later.
Original description
The description as published by the source.
ReverseProxy can forward queries containing parameters not visible to Rewrite functions. When used with a Rewrite function, or a Director function which parses query parameters, ReverseProxy sanitizes the forwarded request to remove query parameters which are not parsed by url.ParseQuery. ReverseProxy does not take ParseQuery's limit on the total number of query parameters (controlled by GODEBUG=urlmaxqueryparams=N) into account. This can permit ReverseProxy to forward a request containing a query parameter that is not visible to the Rewrite function. For example, the query "a1=x&a2=x&...&a10000=x&hidden=y" can forward the parameter "hidden=y" while hiding it from the proxy's Rewrite function.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-39825 has been found in golang.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: upgrade golang to 1.25.10, 1.26.3 or later.
If unsure, ask your IT team or search "golang CVE-2026-39825" on the vendor's site.
CVE-2026-39825 (golang) — CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 1.25.10, 1.26.3 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in golang.
Check the vendor advisory for the affected versions of golang.
Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.
Update to 1.25.10, 1.26.3.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'golang' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'golang' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
golangを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade golang to 1.25.10, 1.26.3ステージング環境で 1.25.10, 1.26.3 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2026-39825 go Fixed in: 1.26.3-r0
- Debian DEBIAN-CVE-2026-39825 golang-1.15
- Ubuntu UBUNTU-CVE-2026-39825 golang-1.10
References
- advisory pkg.go.dev
- patch go.dev
- report go.dev
- web groups.google.com
- web nvd.nist.gov
- web github.com