Git fixes flaw that allows malicious repositories to execute code during recursive clones
A flaw in Git can allow a malicious repository to execute an attacker’s code on a computer that recursively clones it and its submodules. The Git Project fixed it this week in Git 2.56.1, with corresponding fixes for the 2.50 to 2.55 series in 2.50.2, 2.51.3, 2.52.1, 2.53.1, 2.54.1, and 2.55.1.
The fault, followed as CVE-2026-111760is an entire truncation in the way Git manages its index. An extremely long path in a repository may pass Git’s security check, but Git then writes it to disk under a shorter name that an attacker can set to .git.
This allows an attacker to replace a submodule’s .git file with a symbolic link to a folder containing malicious hooks or configuration. Hooks are programs that Git executes at defined points, so once Git uses that folder, the attacker’s code can execute.
Submodules are important here because Git refuses to replace a .git folder with a symlink, but in a freshly cloned submodule, .git is a file.
The fixed versions, listed in the Git project release announcement, disallow such extremely long paths before their length can be shortened.
GitHub, which offers Git in its own tools, explained the fixes in a detailed article. He advises installing a patched version from your operating system or your Git distributor and updating any application that provides its own copy of Git.
The company has already applied the patches to github.com and GitHub Enterprise Cloud. For GitHub Enterprise Server, they are in versions 3.19.15, 3.20.11, 3.21.9 and 3.22.4.
Fixed versions of GitHub Desktop and the GitHub Copilot app are being prepared. GitHub Codespaces and GitHub Actions will also get the Git patched.
Git for Windows had not released a version based on Git 2.56.1 as of 7:09 p.m. UTC as of Tuesday, a check of its version tags by The Hacker News revealed.
While you wait for a patched version to be installed, GitHub suggests these steps, which do not replace patches:
- Only clone from servers you trust.
- Don’t recursively clone repositories you don’t trust.
- Don’t merge content or tags you don’t trust.
- Don’t deal with binary patches or quick import streams from sources you don’t trust.
The Git releases also fix five other flaws:
- CVE-2026-113408: When someone clones an empty repository via the Git v2 protocol, a malicious server can send a branch name containing a path traversal. With the file reference backend, a subsequent update to this branch can then write outside of Git’s reference folder.
- CVE-2026-114467: Merging a tag containing more than two GPG signatures corrupts Git’s stack memory and can cause a denial of service. Hosting services that perform such merges for users may also be affected.
- CVE-2026-114469: A binary patch that expands to a very large size may exceed Git’s patch size limit by around 1 GiB and crash Git with an out-of-bounds read.
- CVE-2026-105437: A very large merge, with many conflicts and a large conflict marker size attribute, can cause Git to write past the end of a buffer that is too small, corrupting heap memory.
- CVE-2026-114466: Three quick import features of git, rewrite-submodules-from, rewrite-submodules-to, and export-pack-edges, could be used to read arbitrary files or to create files and append data to them. Git now rejects them in an input stream unless –allow-unsafe-features is set.
GitLab, which assigned CVE-2026-105437, said that code hosting servers are most likely to be targeted via git merge-tree. A server can run this command to check if a pull or merge request can be merged.
The conflict-marker-size attribute can be set in a .gitattributes file committed to a repository. If a server reads the repository attributes, any user who can push branches and open a pull or merge request can trigger the flaw.
To work around this flaw, servers that cannot yet be upgraded can add conflict-marker-size=7 to each repository’s info/attributes file, or disable these merge checks for untrusted repositories.
Gn tech
