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Fencer Intel
medium 4.1

CVE-2026-97869 json

langchain4j LangChain4j-agentic AgenticScopeJsonSerializationIT.java AgenticScopeSerializer.fromJson deserialization

published 2mo ago modified last mo. also EUVD-2026-87114 , GHSA-gmwr-7wmf-mrjm

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository langchain4j/langchain4j. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
4.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits
0
none known

Summary

A flaw has been found in langchain4j up to 1.5.3-beta10/1.11.10-beta18/1.18.1-beta27. This vulnerability affects the function AgenticScopeSerializer.fromJson of the file AgenticScopeJsonSerializationIT.java of the component LangChain4j-agentic. This manipulation causes deserialization. Remote exploitation of the attack is possible. The attack's complexity is rated as high. It is stated that the exploitability is difficult. The exploit has been published and may be used. Upgrading to version 1.5.3-beta11, 1.11.10-beta19 and 1.18.1-beta28 is able to resolve this issue. Upgrading the affected component is advised. The project maintainer kindly explains: "The issue was reported to us privately on 23 July 2026 and fixed in releases published on 29 July 2026. It is tracked as GHSA-gmwr-7wmf-mrjm. Exploitation requires an application to have enabled AgenticScope persistence, which is opt-in, and an attacker who can already write to that store. All maintained release lines have been patched."

Patch / fix

  • n/a langchain4j 1.5.3-beta11, 1.11.10-beta19, 1.18.1-beta28

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
last mo.

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/afish3201-debug/CVE/blob/main/Insecure%20Jackson%20Default%20Typing%20Leads%20to%20Arbitrary%20Class%20Instantiation%20in%20LangChain4j%20Agentic%20Module.md referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 2.1 CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
CNA 3.1 4.1 CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C
CNA 3.0 4.1 CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C
CNA 2.0 4.3 AV:N/AC:H/Au:M/C:P/I:P/A:P/E:POC/RL:OF/RC:C
CNA 4.0 1.2 CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CNA 3.1 4.1 CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:L
CNA 2.0 4.3 AV:N/AC:H/Au:M/C:P/I:P/A:P

Affected products

  • n/a langchain4j

Classification

Weakness
  • CWE-502 Deserialization of Untrusted Data
  • CWE-20 Improper Input Validation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of langchain4j/langchain4j published their own advisory on GitHub. Reviewed sources take precedence over it.