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🛡️ CVE-2024-1455 — langchain

🟡 CVSS 5.9 — Medium ⚠️ Exploit Public CWE-776 NVD
5.9
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

LangChain's XMLOutputParser vulnerable to XML Entity Expansion

The XMLOutputParser in LangChain uses the etree module from the XML parser in the standard python library which has some XML vulnerabilities; see: https://docs.python.org/3/library/xml.html

This primarily affects users that combine an LLM (or agent) with the XMLOutputParser and expose the component via an endpoint on a web-service.

This would allow a malicious party to attempt to manipulate the LLM to produce a malicious payload for the parser that would compromise the availability of the service.

A successful attack is predicated on:

1. Usage of XMLOutputParser

2. Passing of malicious input into the XMLOutputParser either directly or by trying to manipulate an LLM to do so on the users behalf

3. Exposing the component via a web-service

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is high, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: High — the attacker first has to win a race, learn a secret or otherwise prepare the target.
  • Privileges required: None — an unauthenticated stranger can try it.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: None.
  • Integrity impact: None.
  • Availability impact: High — total loss, or loss the attacker controls.

Weakness class

CVE-2024-1455 is classified as CWE-776: XML Entity Expansion. Nested entity definitions expand enormously when parsed, consuming memory and CPU.

Affected software

CVE-2024-1455 is recorded against 2 packages.

  • langchain (from 0.1.4 up to 0.1.35)
  • langchain-core (fixed in 0.1.35)

Timeline and source

Published on 26 March 2024 and last revised on 17 June 2026. A public exploit is known to exist, which raises the urgency of patching considerably. A vendor advisory or fix has been published. Record sourced from NVD.

References

github.com
huntr.com
github.com
huntr.com

Other advisories for this package

langchain has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-776: XML Entity Expansion) in other software:

Details

Severity MEDIUM
CVSS Score 5.9
CVSS Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE CWE-776
Public Exploit ⚠️ Yes
Source NVD
Published 2024-03-26
Updated 2026-08-20
Modified 2026-06-17

Affected Packages

Software From version Fixed in
langchain 0.1.4 0.1.35
langchain-core — 0.1.35

Similar Threats

Exploit Protection

Are you running langchain?

CVE-2024-1455 carries CVSS 5.9 Medium rating and a public exploit already exists. BotEraser checks your installation against this and other known CVE records, and blocks IPs associated with exploit activity.

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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