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GitHub released security updates for a high-severity vulnerability in GitHub Enterprise Server that could let an unauthenticated remote attacker delete arbitrary files and directories on affected instances. Tracked as CVE-2026-17556, the bug is a path traversal issue caused by unsanitized use of the X-GitHub-Request-Id header as part of a filesystem path for an upload buffer directory, which can then be recursively removed by a cleanup routine. The flaw is rated CVSS 8.8 and mapped to CWE-22.
According to the advisories, the issue affects all GitHub Enterprise Server versions prior to 3.22, including 3.21.x before 3.21.4, 3.20.x before 3.20.6, 3.19.x before 3.19.10, 3.18.x before 3.18.13, and 3.17.x before 3.17.19. The vulnerability requires only network access, does not require authentication, and remains exploitable even when private mode is enabled. Authorities and vendor guidance recommend upgrading immediately to the fixed releases referenced in GitHub’s security bulletins.
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2 events from the most recent confirmed update back to the earliest known activity.
A CVE entry disclosed CVE-2026-17556 as a high-severity path traversal vulnerability in GitHub Enterprise Server caused by unsanitized use of the X-GitHub-Request-Id header in a filesystem path. GitHub said all versions prior to 3.22 were affected and that exploitation required only network access, with no authentication needed.
GitHub released security updates for GitHub Enterprise Server to remediate CVE-2026-17556, a high-severity path traversal flaw that could let an unauthenticated remote attacker delete arbitrary files and directories. The fixes were issued in versions 3.21.4, 3.20.6, 3.19.10, 3.18.13, and 3.17.19.
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GitHub released urgent security updates for GitHub Enterprise Server to fix multiple severe vulnerabilities affecting versions `3.16` through `3.20`, led by **CVE-2026-9312**, a critical pre-authentication SSRF flaw in an upload endpoint. The bug allowed unauthenticated attackers to craft requests with path traversal content and force the appliance to make internal HTTP requests, potentially exposing internal services, credentials, and configuration data. GitHub said the issue was reported through its bug bounty program and remediated in `3.16.20`, `3.17.17`, `3.18.11`, `3.19.8`, `3.20.4`, and `3.21.1`. The updates also address the high-severity Linux kernel local privilege-escalation flaws **CVE-2026-43284** and **CVE-2026-43500**, known as **Dirty Frag**, which could let a local user gain root on vulnerable appliances. Additional fixes and hardening cover a timing side-channel issue and another SSRF-related weakness tied to package and notebook-related functionality, including environments with GitHub Packages enabled or private mode disabled. GitHub revoked the signing key for GHES release packages and instructed administrators to rotate trusted local GPG public keys before installing the patched releases, urging rapid upgrades for internet-facing and shared multi-tenant deployments.
Jul 20, 2026
GitHub disclosed and patched **CVE-2026-3854**, a critical command-injection flaw in its `git push` pipeline that allowed an authenticated user with repository push access to trigger remote code execution using a single crafted push. Wiz reported the bug on March 4, and GitHub said it reproduced the issue within about 40 minutes and deployed a fix to GitHub.com within roughly two hours, later publishing patches for supported GitHub Enterprise Server releases including **3.14.24, 3.15.19, 3.16.15, 3.17.12, 3.18.6, and 3.19.3**. The vulnerability stemmed from unsanitized user-supplied push option values being inserted into internal `X-Stat` headers, enabling attackers to inject trusted metadata, bypass sandboxing, and execute commands as the `git` service user. Researchers said the flaw could have led to **full server compromise** on GitHub Enterprise Server and, on GitHub.com, code execution on shared storage infrastructure where millions of repositories were accessible to the git service account, creating potential cross-tenant exposure. GitHub said forensic analysis and telemetry found **no evidence of malicious exploitation** and no indication that customer data was accessed, modified, or exfiltrated, but urged Enterprise Server administrators to upgrade immediately and review logs for suspicious push activity. Wiz described the bug as easy to exploit and highlighted its use of AI-assisted reverse engineering tools, including **IDA MCP**, to uncover the issue in GitHub’s closed-source components.
Jul 23, 2026
A vulnerability tracked as **`CVE-2024-0200`** allowed attackers with organization owner privileges to abuse an unsafe Ruby `Kernel#send()` call in GitHub’s organization repository settings flow and invoke unintended zero-argument methods on `Repository` objects. Researchers showed the bug could be used to trigger `Repository::GitDependency#nw_fsck()` and leak roughly **2 MB of environment variables** from a production GitHub.com container, exposing access keys, secrets, and internal configuration because spawned git processes inherited the parent environment. The issue affected **GitHub.com** and **GitHub Enterprise Server (GHES)** instances with GitHub Actions enabled, but the impact was more severe on GHES. STAR Labs reported that leaked variables on GHES could include `ENTERPRISE_SESSION_SECRET` and other Marshal-related secrets, which could be chained with forged Rails session cookies and an unsafe `Marshal.load` path to achieve **remote code execution**. GitHub hotfixed GitHub.com on December 26, 2023, and later released a patch and advisory, while recommended mitigations included allowlisting the `rid_key` parameter, reducing environment variables passed to git processes, rotating exposed secrets, and monitoring `repository_items` requests for abnormal `rid_key` values.
Jun 29, 2026