Environment-secret extraction via unescaped serialization markers
Published Dec 23, 2025 · Updated Dec 23, 2025
Serialization injection in LangChain Core before 0.3.81 and 1.0.0 through 1.2.4 allows remote attackers to read environment secrets. The dumps() and dumpd() functions leave user-controlled dictionaries with an lc marker unescaped, so load() and loads() interpret them as trusted serialized objects. Exploitation requires an application to serialize or deserialize attacker-controlled structures; the former secrets_from_env default exposes named environment variables, while trusted-namespace constructors can trigger network or file side effects.
Summary
What happened
Serialization injection in LangChain Core before 0.3.81 and 1.0.0 through 1.2.4 allows remote attackers to read environment secrets. The dumps() and dumpd() functions leave user-controlled dictionaries with an lc marker unescaped, so load() and loads() interpret them as trusted serialized objects. Exploitation requires an application to serialize or deserialize attacker-controlled structures; the former secrets_from_env default exposes named environment variables, while trusted-namespace constructors can trigger network or file side effects.
The record
- CVE
- CVE-2025-68664
- Published
- Dec 23, 2025
- Updated
- Dec 23, 2025
- Vendor
- LangChain
- Product
- LangChain
- Classifications
- CWE-502
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 23, 2025CVE publishedPublication date reported by the CVE source.
- Dec 23, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 0.3.81
- Affected versionversion=>= 1.0.0, < 1.2.5
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GitHub advisory environment-secret exploit exampleproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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