Git for Windows: git-credential-wincred OAuth Store Heap Overflow
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 2.55.0.windows.3
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 2.55.0.windows.3.
- Exploitation?/40Exploitation: unknown (data gap). No CISA SSVC exploitation rating yet
- Exposure?/25Exposure: unknown (data gap). No advisory context yet
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity4.4/10CVSS 4.4
- No patch0/5No signal
What would change the score
- Would score about 59 if added to CISA KEV
- Would score about 54 if CISA's SSVC rates exploitation active
- Would score about 26 if advisories confirm default setups are exposed
CVE-2026-100407 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 4.4 (medium) and affects git; fixed in 2.55.0.windows.3.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 4/100 · provisional
- Fix
- Fixed in 2.55.0.windows.3
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
Git for Windows' git-credential-wincred helper, used when storing OAuth credentials, can be corrupted by a heap overflow in its credential-store operation. A local attacker who gets a user to run the affected store operation could corrupt the helper and cause the OAuth credential to go unsaved while Git reports success, though the flaw is not known to be exploited.
Read the original description
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 to do
Upgrade to a fixed version: 2.55.0.windows.3.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- git-for-windows git
From 2.44.0.windows.1 · fixed in 2.55.0.windows.3
Evidence 3
- Advisory
- Repository
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-100407
Is CVE-2026-100407 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-100407?
git: from 2.44.0.windows.1 before 2.55.0.windows.3.Source: cve.now feed data
How do I fix CVE-2026-100407?
Upgrade to a fixed version: 2.55.0.windows.3.Source: cve.now feed data