Vulnerability in github.com/portainer/portainer (CVE-2026-44883)
Summary
Vulnerability in github.com/portainer/portainer (CVE-2026-44883). Successful exploitation can lead to full system takeover. Exploitable via Referer. Mitigation: upgrade to 2.41.0 or later.
Original description
The description as published by the source.
Summary
Portainer's authentication middleware accepts JWT bearer tokens passed as the ?token= URL query parameter on any authenticated API endpoint, in addition to the standard Authorization: Bearer header. URLs are recorded in reverse-proxy access logs, browser history, and HTTP Referer headers on outbound navigation, so any JWT passed this way can be harvested by anyone with access to those logs or by an external site the user subsequently visits. A leaked token grants the full privileges of the user it was issued to, until the token expires (default 8 hours, configurable).
The ?token= parameter was used by Portainer's browser-based container attach, exec, and pod shell features, so any user with exec or attach rights on a container was exposed — not only administrators.
Severity
High
Attack complexity is High because exploitation depends on the attacker obtaining a leaked token from a log, referer, or shared URL. Once obtained, a leaked token grants the privileges of the user it was issued to; for administrator tokens this compromises confidentiality, integrity, and availability of Portainer itself and of every Docker/Kubernetes environment it manages — container exec and stack deployment make host-level compromise reachable, so subsequent-system impact is also High.
Affected Versions
Query-parameter token acceptance has existed since JWT authentication was introduced in Portainer.
Fixes are included in the following releases:
| Branch…
Source: GitHub Security Advisories (Global) 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-2026-44883 has been found in github.com/portainer/portainer.
Attackers can target a specific entry point like Referer over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 7.5/10.
What to do: upgrade github.com/portainer/portainer to 2.41.0 or later.
If unsure, ask your IT team or search "github.com/portainer/portainer CVE-2026-44883" on the vendor's site.
CVE-2026-44883 (github.com/portainer/portainer) — CWE-598 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: Referer / token / extractBearerToken / Authorization
Patched: 2.41.0 — 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 (CWE-598) exists in github.com/portainer/portainer. Attackers reach the vulnerable code path via Referer without authentication.
Check the vendor advisory for the affected versions of github.com/portainer/portainer. Attack surface: Referer / token / extractBearerToken / Authorization.
Severity: High (CVSS 7.5/10). Successful exploitation can lead to full system takeover.
Update to 2.41.0.
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 'github.com/portainer/portainer' . 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
-
1Identify exposure identify
grep -r 'github.com/portainer/portainer' . | 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
github.com/portainer/portainer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 github.com/portainer/portainer to 2.41.0ステージング環境で 2.41.0 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
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com