CVE-2026-125121VulnerabilityPublished 10 Nov 2026

compose-lint: Text

Affects compose-lintSource GCVE Database

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Authoritative record:CVE-2026-125121· Medium 5.3

Not known to be exploited · CVSS 5.3 Medium : upgrade to 0.32.0 when convenient.

Data as of 10 Nov 2026, 19:05 UTC

CVSS 4.0 base score

5.3Medium

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

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitHub_M)	CVSS 4.0	5.3

Patch: Available – fixed in 0.32.0

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

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: Passive
Vulnerable system confidentiality: None
Vulnerable system integrity: Low
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: Low
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: 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: Passive: Successful exploitation of this vulnerability requires limited interaction by the targeted user with the vulnerable system and the attacker’s payload. These interactions would be considered involuntary and do not require that the user actively subvert protections built into the vulnerable system.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
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: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Subsequent 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 10 Nov 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 10 Nov 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

Upgrade compose-lint to 0.32.0.

Affected software

Product	Affected	Fixed in
PyPIcompose-lint	Affected >=0.31.0 <0.32.0	Fixed in 0.32.0

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Description

### Impact 0.31.0 fixed GHSA-6f4g-xm8v-pgv6, where text from a Compose file became GitHub Actions workflow commands in compose-lint's output. The fix escapes the command openers in everything compose-lint prints, and the 0.31.0 changelog says the report "escapes both openers (also covering Azure Pipelines)". Five paths were left open: - **Unicode whitespace before a line-leading `::`.** The runner strips all Unicode whitespace from the start of a line before it looks for a command. compose-lint only accounted for spaces and tabs, so a no-break space or another Unicode space ahead of `::` is not escaped. It can come from a Compose value, or from a file name: the text report's file heading and per-file summary, and the `fix` summary on stderr, start with the path as given, so a directory named with a leading no-break space followed by `::` puts a command at the start of a line. This reaches those lines, the text report's fix guidance, the `fix` dry-run diff, and continuation lines of stderr diagnostics. - **JSON and SARIF printed to stdout.** `--format json` and `--format sarif` output never passed through the sanitizer, so `##[` inside a service name or other value reaches the log intact when the output isn't redirected to a file. - **Command-line errors.** When a repository path reaches compose-lint's arguments without a `--` before it, the argument parser prints it raw in its error message. That includes a carriage return, which the runner treats as a line break, so a command can also start a new line there. - **Azure Pipelines.** `##vso[` logging commands were not escaped on any path, despite the changelog's Azure claim. - **An error message in the GitHub Action (0.30.0 and 0.31.0).** When `sarif-file:` names a file in a subdirectory that can't be created, the Action prints the directory's resolved path in an error message, outside the window in which it turns command processing off. A pull request can commit a symlink on that path to a directory whose name contains a newline followed by a command. The documented setup, `sarif-file: results.sarif` at the repository root, is not affected. A pull request can therefore create annotations, fold or hide parts of the job log, or issue other commands the runner accepts, when CI runs compose-lint over it, before anyone reviews it. The pass/fail result is not changed. Affected setups are those that print compose-lint's output to a CI log without the GitHub Action: the `compose-lint` package run directly in a workflow, the pre-commit hook run in CI, and the Docker image. The pre-commit hook is affected in its default configuration: it passes each changed file's path to compose-lint, and a path whose directory name starts with Unicode whitespace and `::` reaches the report's file heading. The JSON/SARIF and command-line paths also need output left on stdout, or `args:` without the documented trailing `--`, which is why they alone would score lower. The GitHub Action turns command processing off around each compose-lint run, so of these paths only its own error message affects it, and only when `sarif-file:` points into a subdirectory. That setup is outside the documented one, which is why that path alone would also score lower. Found during an internal pre-1.0 security review. **Docker image.** `composelint/compose-lint` tag 0.31.0, the matching minor tag, and `latest` are affected. Releases before 0.31.0 are covered by GHSA-6f4g-xm8v-pgv6, except the Action's error message, which also affects Action 0.30.0. ### Patches Fixed in 0.32.0. The line-start escaping covers every character the runner strips before `::`, so it holds for quoted values and file names alike. JSON and SARIF on stdout escape `##[` inside strings as `\u005b`, which decodes to the same data. argparse's own messages go through the same sanitizer. `##vso[` is escaped everywhere. In the Action, the SARIF-directory error names the `sarif-file:` input as written. ### Workarounds - Upgrade to 0.32.0 or later. - On GitHub Actions, use the `tmatens/compose-lint` Action, or bracket the compose-lint step with `::stop-commands::<random token>` and `::<token>::`, as the Action does. - In the Action, keep `sarif-file` at the workspace root, for example `sarif-file: results.sarif`. - Write `--format json` and `--format sarif` output to a file rather than the log. - End the pre-commit hook's `args:` with `--`. This closes the command-line path only; it does not stop a file name at the start of a report line, so in CI also bracket the pre-commit step with `::stop-commands::` as above. - On Azure Pipelines, don't print compose-lint's output from runs over untrusted pull requests to the job log. ### Reproduction On compose-lint 0.31.0 on a GitHub-hosted runner (runner 2.337.0), each of the following creates an annotation: - a Compose file with `image: "nginx\n\u00a0::notice::X"`, linted with the text report; - a directory named `\u00a0::notice::X` (a no-break space, then `::notice::X`) holding a `comp

CWE-117Improper Output Neutralization for Logs (opens in a new tab)
Base weaknessLikelihood of exploit: MediumOWASP Top 10 A09:2025: Security Logging & Alerting Failures (opens in a new tab)
The product constructs a log message from external input, but it does not neutralize or incorrectly neutralizes special elements when the message is written to a log file.
Implementation · Input Validation
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.
Implementation · Output Encoding
Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8.
Implementation · Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174).
OWASP Cheat Sheets
Logging (opens in a new tab)
Content Security Policy (opens in a new tab)
Application Logging Vocabulary (opens in a new tab)
OWASP ASVS 4.0.3
V7.3.1 (opens in a new tab)
V14.4.6 (opens in a new tab)
V14.4.4 (opens in a new tab)
Attack patterns
Audit Log Manipulation (opens in a new tab)
Web Server Logs Tampering (opens in a new tab)
Log Injection-Tampering-Forging (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-150Improper Neutralization of Escape, Meta, or Control Sequences (opens in a new tab)
Variant weakness
The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as escape, meta, or control character sequences when they are sent to a downstream component.
Developers should anticipate that escape, meta and control characters/sequences will be injected/removed/manipulated in the input vectors of their product. Use an appropriate combination of denylists and allowlists to ensure only valid, expected and appropriate input is processed by the system.
Implementation · Input Validation
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.
Implementation · Output Encoding
While it is risky to use dynamically-generated query strings, code, or commands that mix control and data together, sometimes it may be unavoidable. Properly quote arguments and escape any special characters within those arguments.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
Server Side Request Forgery Prevention (opens in a new tab)
Unvalidated Redirects and Forwards (opens in a new tab)
Cross Site Scripting Prevention (opens in a new tab)
OWASP ASVS 4.0.3
V1.5.1 (opens in a new tab)
V5.2.2 (opens in a new tab)
Attack patterns
Email Injection (opens in a new tab)
Using Meta-characters in E-mail Headers to Inject Malicious Payloads (opens in a new tab)
Web Server Logs Tampering (opens in a new tab)
Log Injection-Tampering-Forging (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

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Exploitation evidence

What to do

Affected software

Description

WeaknessesCWE-117, CWE-150

Technical details

References

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