CVE-2026-78678
ADVISORY - githubSummary
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
Common Weakness Enumeration (CWE)
Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
GitHub
CVSS SCORE
6.5medium| Package | Type | OS Name | OS Version | Affected Ranges | Fix Versions |
|---|---|---|---|---|---|
| gitpython | pypi | - | - | <=3.1.58 | 3.1.59 |
CVSS:3 Severity and metrics
The CVSS metrics represent different qualitative aspects of a vulnerability that impact the overall score, as defined by the CVSS Specification.
The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone). One example of an Adjacent attack would be an ARP (IPv4) or neighbor discovery (IPv6) flood leading to a denial of service on the local LAN segment (e.g., CVE-2013-6014).
Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component.
The attacker requires privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
The vulnerable system can be exploited without interaction from any user.
An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
There is a total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
There is no loss of trust or accuracy within the impacted component.
There is no impact to availability within the impacted component.
NIST
2.8
CVSS SCORE
7.1highAlpine
-
Debian
-
Ubuntu
-
CVSS SCORE
N/AmediumPypA
PYSEC-2026-3788
-
CVSS SCORE
7.1highminimos
MINI-c8j7-qv5m-qfj7
-