---
id: "CVE-2026-121820"
page: "https://infrastack.ai/live/CVE-2026-121820"
kind: "vulnerability"
aliases: ["CVE-2026-121820"]
title: "armeria-saml: unbounded decompression lets remote attackers exhaust server memory"
severity: "high"
cvss: 8.7
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["armeria-saml", "java", "package", "saml", "sso"]
not_affected_if: ["http-post-binding-only", "no-saml-sso"]
published_at: "2026-11-06T08:17:20+00:00"
first_seen_at: "2026-11-06T08:40:33+00:00"
updated_at: "2026-11-06T08:42:30+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121820", "first_seen_at": "2026-11-06T08:40:33+00:00"}]
exploit_sources: []
---

# armeria-saml: unbounded decompression lets remote attackers exhaust server memory

Link for people: https://infrastack.ai/live/CVE-2026-121820 (this .md is for agents)

armeria-saml's HTTP-Redirect binding decompresses incoming SAML messages without an output size limit before checking the signature. An unauthenticated attacker can send a small compressed payload that expands to exhaust server memory and crash the service.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the armeria-saml version in the project's dependency file (for example `armeria-saml` in build.gradle or pom.xml) and see whether it is below `1.43.0`
- Check whether the application accepts SAML HTTP-Redirect binding requests

## Fix

- armeria-saml: upgrade to `1.43.0` or later

## Timeline

- 2026-11-06T08:40:33+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121820

## Documents

- [advisory] Vendor advisory: github.com https://github.com/line/armeria/security/advisories/GHSA-6hgp-j5h7-33m3

## From the sources

A vulnerability has been identified in armeria-saml versions prior to 1.43.0, where the HTTP-Redirect binding decoder decompresses attacker-supplied SAML messages without limiting the output size before signature validation, allowing an unauthenticated remote attacker to exhaust server memory and cause a denial of service.

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