CVE-2026-100407git-for-windows git out-of-bounds write
CVE-2026-100407 is a out-of-bounds write in git-for-windows git, rated medium (4.4 on CVSS 3.1).
Why this priority: Medium severity, with no exploitation signal.
Published · Updated · NVD status: Received
What it is
Code writes past the end of a buffer, corrupting memory in ways an attacker can often turn into code execution.
How it is reached
An attacker can exploit it by someone who can already run code or sign in on the machine, without an account, but someone has to act first, such as opening a file or following a link.
What an attacker gains
The direct impact is limited: partial access to data or a partial outage. In practice, this kind of flaw lets an attacker crash the process, read memory, or in the worst case run code.
Is it being exploited?
CISA's SSVC assessment notes a public proof of concept. EPSS estimates a 0.12% chance of exploitation activity in the next 30 days, higher than 2% of scored CVEs.
What to do
- Upgrade git-for-windows git to 2.55.0.windows.3 or later.
- Limit who can run code or sign in on the hosts that run it.
- Warn the people who use it, and filter files and links on the way in.
Description from NVD
Git for Windows is the Windows port of Git. From 2.44.0.windows.1 until 2.55.0.windows.3, the git-credential-wincred store operation in contrib/credential/wincred/git-credential-wincred.c uses _scwprintf() to size a formatted wide-character credential buffer without space for the terminating NUL when both password and oauth_refresh_token are present. The operation also passes a byte count to _snwprintf_s() where a wide-character count is required, allowing the terminator to be written one WCHAR past the heap allocation before CredWriteW() persists the credential. The resulting fixed two-byte NUL overwrite can terminate the helper with Windows heap-corruption status and can cause git credential approve to report success even though the OAuth credential was not stored. This issue is fixed in version 2.55.0.windows.3.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Native code: operating systems, browsers and firmware. The flaw sits wherever native code reads untrusted data.
- Network appliances and media or file parsers. The flaw sits wherever native code reads untrusted data.
Trust boundaries in play
- Host boundary. The attacker needs a foothold on the machine first; the flaw turns a small foothold into a bigger one.
- People who open files and links. Mail, chat and browsers are the delivery path.
- Wherever native code reads untrusted data. An attacker who crosses it can crash the process, read memory, or in the worst case run code.
Questions to answer about your own systems
- Where does git-for-windows git run in your systems, and at which version?
- Which of those hosts also run code or users you do not fully trust?
- What can it reach once compromised: which data stores, secrets and services?
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.