Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessAuthenticate as low-privileged GitLab user controlling a K8s agent
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DeliveryTrigger Kubernetes proxy request
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ExploitExploit improper redirect validation (open redirect)
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ExecutionTokens forwarded to attacker-controlled server
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ImpactHarvest leaked authentication tokens
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V3 - Web Frontend Security Redirect URL validation
MITRE ATT&CK
1 technique across 1 tactic: Initial Access The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Exploitation requires an authenticated user who controls a GitLab Kubernetes agent, and depends specifically on the GitLab Kubernetes proxy feature performing a redirect that is not properly validated (CWE-601 open redirect). The advisory explicitly scopes this to 'certain conditions,' consistent with CVSS AC:H. Limiting factors that reduce realistic risk: the attacker must already hold valid low-privileged credentials (PR:L) and control over a Kubernetes agent, the attack requires user interaction (UI:R), and only deployments that actually use the GitLab Kubernetes agent/proxy integration are exposed - instances without Kubernetes integration are not affected. The payoff is leakage of sensitive authentication tokens to an attacker-chosen server rather than direct code execution or data modification. |
| Impact | This is a genuine but moderate-priority issue, not a top-tier emergency. The CVSS 3.1 vector (AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:N/A:N = 5.8 Medium) tempers the network attack vector with three significant brakes: high attack complexity (the advisory itself says 'under certain conditions'), a requirement that the attacker already hold low-privileged authenticated access AND control a Kubernetes agent (PR:L), and required user interaction (UI:R). The scope change (S:C) and high confidentiality impact (C:H) reflect that the real damage is the leakage of sensitive authentication tokens to an unintended server - a meaningful secret-exposure outcome rather than code execution (I:N/A:N). Signals are mostly aligned and relatively low-urgency: POC/exploit code is publicly available (a HackerOne report), which raises practical likelihood, but there is NO CISA KEV listing and no EPSS score was provided in the input, so there is no evidence of active or widespread exploitation. The combination of public POC + high preconditions + no KEV points to a targeted, opportunistic risk against GitLab instances that use the Kubernetes agent integration, rather than mass exploitation. EPSS is absent from the input and should be checked separately before final prioritization. |
| Exploit ScenarioDerived | An authenticated GitLab user who controls a Kubernetes agent configures or triggers the Kubernetes proxy so that an improperly validated redirect points to an attacker-controlled server; when the proxy follows the redirect it forwards sensitive authentication tokens to that unintended destination. A public proof-of-concept exists (HackerOne report #3597095), but the required control over a Kubernetes agent and the 'certain conditions' (reflected in CVSS AC:H and UI:R) limit this to attackers who already have a foothold in the GitLab/Kubernetes integration. |
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Alert meAnalysisAIv1 – Oct 13, 2026
Authentication token leakage in GitLab CE/EE (all versions from 13.11 before 19.2.8, 19.3 before 19.3.5, and 19.4 before 19.4.2) allows an authenticated user who controls a Kubernetes agent to redirect the Kubernetes proxy to an unintended server, exposing sensitive authentication tokens. Exploitation requires user interaction and only affects instances using the GitLab Kubernetes agent/proxy integration; publicly available exploit code exists. This moderate-severity issue (CVSS 5.8) is not a top-tier emergency but should be patched by affected deployments.
RemediationAI
Vendor-released patch: upgrade to GitLab 19.2.8, 19.3.5, or 19.4.2. For instances that cannot immediately patch, disable the Kubernetes agent/proxy integration if it is not required, or restrict control of Kubernetes agents to trusted users; however, these are compensating controls with trade-offs, as disabling the integration removes Kubernetes functionality and restricting users may not fully prevent abuse if a trusted user is compromised. Refer to the vendor advisory at https://docs.gitlab.com/releases/patches/patch-release-gitlab-19-4-2-released/ and the work item at https://gitlab.com/gitlab-org/gitlab/-/work_items/598965. Public exploit code exists, so prioritize patching for deployments that use the Kubernetes agent/proxy integration.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
The vulnerability is a CWE-601 open redirect in the GitLab Kubernetes proxy, a component that mediates access between GitLab and Kubernetes clusters via the GitLab agent. An authenticated user with control over a Kubernetes agent can manipulate a redirect in the proxy so that authentication tokens intended for a legitimate Kubernetes API server are sent to an attacker-controlled server. The CVSS vector CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:N/A:N indicates network exploitable with high complexity, low privileges required, user interaction needed, scope changed, high confidentiality impact, and no integrity or availability impact. The CPE cpe:2.3:a:gitlab:gitlab:*:*:*:*:*:*:*:* confirms GitLab CE/EE as the affected product. The open redirect class arises from improper validation of redirect URLs, allowing token leakage when the proxy follows an unvalidated redirect.
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Severity by source
AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:N/A:N
Authenticated agent control gives PR:L, the 'certain conditions' justify AC:H, redirect delivery implies UI:R, token leakage to another system is S:C with C:H and no integrity/availability impact.
Primary rating from Vendor (GitLab).
CVSS VectorVendor: GitLab
Lifecycle Timeline
2DescriptionCVE.org
GitLab has remediated an issue in GitLab CE/EE affecting all versions from 13.11 before 19.2.8, 19.3 before 19.3.5, and 19.4 before 19.4.2 that, under certain conditions, could have allowed an authenticated user controlling a Kubernetes agent to cause sensitive authentication tokens to be sent to an unintended server due to improper redirect validation in the Kubernetes proxy.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
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