| Package | Affected versions | Patched versions |
|---|---|---|
| langchain-core | < 1.2.22 | 1.2.22 |
| langchain core | < 1.2.22 | 1.2.22 |
Multiple functions in langchain_core.prompts.loading read files from paths embedded in deserialized config dicts without validating against directory traversal or absolute path injection. When an application passes user-influenced prompt configurations to load_prompt() or load_prompt_from_config(), an attacker can read arbitrary files on the host filesystem, constrained only by file-extension checks (.txt for templates, .json/.yaml for examples).
Note: The affected functions (load_prompt, load_prompt_from_config, and the .save() method on prompt classes) are undocumented legacy APIs. They are superseded by the dumpd/dumps/load/loads serialization APIs in langchain_core.load, which do not perform filesystem reads and use an allowlist-based security model. As part of this fix, the legacy APIs have been formally deprecated and will be removed in 2.0.0.
Package: langchain-core
File: langchain_core/prompts/loading.py
Affected functions: _load_template(), _load_examples(), _load_few_shot_prompt()
High
The score reflects the file-extension constraints that limit which files can be read.
| Config key | Loaded by | Readable extensions |
|---|---|---|
template_path, suffix_path, prefix_path | _load_template() | .txt |
examples (when string) | _load_examples() | .json, .yaml, .yml |
example_prompt_path | _load_few_shot_prompt() | .json, .yaml, .yml |
None of these code paths validated the supplied path against absolute path injection or .. traversal sequences before reading from disk.
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Scan my site freeAn attacker who controls or influences the prompt configuration dict can read files outside the intended directory:
.txt files: cloud-mounted secrets (/mnt/secrets/api_key.txt), requirements.txt, internal system prompts.json/.yaml files: cloud credentials (~/.docker/config.json, ~/.azure/accessTokens.json), Kubernetes manifests, CI/CD configs, application settingsThis is exploitable in applications that accept prompt configs from untrusted sources, including low-code AI builders and API wrappers that expose load_prompt_from_config().
from langchain_core.prompts.loading import load_prompt_from_config
# Reads /tmp/secret.txt via absolute path injection
config = {
"_type": "prompt",
"template_path": "/tmp/secret.txt",
"input_variables": [],
}
prompt = load_prompt_from_config(config)
print(prompt.template) # file contents disclosed
# Reads ../../etc/secret.txt via directory traversal
config = {
"_type": "prompt",
"template_path": "../../etc/secret.txt",
"input_variables": [],
}
prompt = load_prompt_from_config(config)
# Reads arbitrary .json via few-shot examples
config = {
"_type": "few_shot",
"examples": "../../../../.docker/config.json",
"example_prompt": {
"_type": "prompt",
"input_variables": ["input", "output"],
"template": "{input}: {output}",
},
"prefix": "",
"suffix": "{query}",
"input_variables": ["query"],
}
prompt = load_prompt_from_config(config)
Update langchain-core to >= 1.2.22.
The fix adds path validation that rejects absolute paths and .. traversal sequences by default. An allow_dangerous_paths=True keyword argument is available on load_prompt() and load_prompt_from_config() for trusted inputs.
As described above, these legacy APIs have been formally deprecated. Users should migrate to dumpd/dumps/load/loads from langchain_core.load.