GHSA-5xxx-qhh7-9287 CVE-2026-78678 PYSEC-2026-3788
GitPython: Incomplete unsafe_git_revision_options denylist omits --contents/-S, enabling arbitrary file read via Repo.blame()
- Severity
- 0.0 / 10
- Medium · CVSS 4.0
- Exploit chance (EPSS)
- 0.41%
- Chance of exploitation in the next 30 days. Higher than 35.47% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
- CWE-88 Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
- Fix
3.1.59- Upgrade gitpython to this version or later
Description
Summary
Repo.blame() / Repo.blame_incremental() guard forwarded revision options against unsafe_git_revision_options, but that denylist only contains the file-WRITE options --output/-o. git blame also honors --contents <file> and -S <file>, which cause the file's lines to be echoed into the blame result — an arbitrary file READ. Neither option is in the denylist, so a caller-influenced revision value of --contents=<path> passes the guard and leaks file contents. This is a distinct sink-option and impact class (READ) from GHSA-956x-8gvw-wg5v (which addressed the blame --output WRITE), directly analogous to GHSA-539m-9xh6-q6rr (archive READ gap accepted separately from the archive write/exec advisory).
Root Cause
unsafe_git_revision_options = ["--output","-o"] (git/repo/base.py:188). The rev string is passed to _option_candidates([rev], kwargs) and placed BEFORE the -- separator (base.py:841). The canonical name of --contents=... is contents, which is not on the denylist, so no UnsafeOptionError is raised. The trailing -- protects only the pathspec, not the option before the revision.
Impact
Arbitrary local file read at the privileges of the host process; the file's line contents appear in the blame result returned to the caller. Pure VALUE control (the caller forwards a user-influenced revision string). Default allow_unsafe_options=False.
Proof of Concept
result = repo.blame("--contents=/etc/passwd", "a.txt")
# result rows carry the victim file's line text
Attack Chain
- Entry: app calls
repo.blame(rev, file)with attackerrev="--contents=/etc/passwd"(or kwargcontents="/etc/passwd", or-S). - Check:
Git.check_unsafe_options(_option_candidates([rev,...], kwargs), unsafe_git_revision_options)@ base.py:841. Guard: denylist =["--output","-o"]only. Bypass proof: canonical namecontents∉ denylist → no error. - Sink:
self.git.blame(rev, "--", file, p=True, ...). argv (observed):['git','blame','-p','--contents=<secret>','HEAD','--','a.txt']. - Impact: blame result rows carry the victim file's line text.
Bypass Evidence
Independently reproduced (independent test harness, default allow_unsafe_options=False): blame('--contents=<secret>','a.txt') → guard PASSED; result rows = ['GATE_SECRET_LINE_A','GATE_SECRET_LINE_B']. Control: blame('--output=…') still BLOCKED (guard active on this path). -S kwarg argv also reaches git unguarded.
Affected Versions
GitPython <= 3.1.58 (denylist present verbatim on the latest release tag).
Suggested Fix
Prefer an allowlist of blame options; at minimum add --contents/-S (and any other path-taking blame options) to unsafe_git_revision_options, and make the membership rule "the option takes a filesystem path" rather than "the option writes output".
Reported by zx (Jace) — GitHub: @manus-use
Affected versions
PyPI
| Package | Vulnerable | Fixed in |
|---|---|---|
| gitpython | < 3.1.59 |
3.1.59 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
gitpython PyPI → 3.1.59
- pip
pip install --upgrade "gitpython>=3.1.59"- poetry
poetry add "gitpython>=3.1.59"- uv
uv add "gitpython>=3.1.59"
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- Low
- User interaction
- None
- Confidentiality (vulnerable system)
- High
- Integrity (vulnerable system)
- None
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
- Exploit maturity
- Not defined
- Scope
- X
CVSS 3.1 6.5
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Weakness
CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
How to prevent it
- Architecture and Design: Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
The product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string.
How to prevent it
- Implementation: Where possible, avoid building a single string that contains the command and its arguments. Some languages or frameworks have functions that support specifying independent arguments, e.g. as an array, which is used to automatically perform the appropriate quoting or escaping while building the command. For example, in PHP, escapeshellarg() can be used to escape a single argument to system(), or exec() can be called with an array of arguments. In C, code can often be refactored from using system() - which accepts a single string - to using exec(), which requires separate function arguments for each parameter.
- Architecture and Design: Understand all the potential areas where untrusted inputs can enter your product: parameters or arguments, cookies, anything read from the network, environment variables, request headers as well as content, URL components, e-mail, files, databases, and any external systems that provide data to the application. Perform input validation at well-defined interfaces.
- Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
- Implementation: Directly convert your input type into the expected data type, such as using a conversion function that translates a string into a number. After converting to the expected data type, ensure that the input's values fall within the expected range of allowable values and that multi-field consistencies are maintained.
- Implementation: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180, CWE-181). Make sure that your application does not inadvertently decode the same input twice (CWE-174). Such errors could be used to bypass allowlist schemes by introducing dangerous inputs after they have been checked. Use libraries such as the OWASP ESAPI Canonicalization control. Consider performing repeated canonicalization until your input does not change any more. This will avoid double-decoding and similar scenarios, but it might inadvertently modify inputs that are allowed to contain properly-encoded dangerous content.
- Implementation: When exchanging data between components, ensure that both components are using the same character encoding. Ensure that the proper encoding is applied at each interface. Explicitly set the encoding you are using whenever the protocol allows you to do so.
- Implementation: When your application combines data from multiple sources, perform the validation after the sources have been combined. The individual data elements may pass the validation step but violate the intended restrictions after they have been combined.
- Testing: Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-83vg-56qc-22m7 GitPython validates a submodule's ".git" path only after cloning into it (RCE) | High | Also affects gitpython |
| GHSA-gq48-pqfc-9p58 GitPython: Submodule.move() follows an attacker-committed intermediate symlink outside the worktree | Medium | Also affects gitpython |
| GHSA-23mf-xhv8-69c2 GitPython: arbitrary file read via attacker-controlled branch name in `Head.checkout()` (incomplete fix of CVE-2026-78679) | High | Also affects gitpython |
| GHSA-f9j4-qggq-h239 GitPython Remote.pull() refspec bypasses the --upload-pack unsafe-option guard, enabling arbitrary command execution | Critical | Also affects gitpython |
| GHSA-w8jc-g24h-crhw GitPython command wrappers omit unsafe protocol and option checks | High | Also affects gitpython |
| GHSA-m64x-33q8-m5h7 GitPython parse_actor_and_date() is vulnerable to quadratic backtracking on malformed identity lines | High | Also affects gitpython |
| GHSA-fx3j-rwgx-fr94 GitPython: separate_git_dir leaks env vars via crafted .gitmodules submodule name | High | Also affects gitpython |
| GHSA-59cr-6r3x-644w GitPython submodule update path traversal can write outside the repository | Medium | Also affects gitpython |
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