---
id: "CVE-2026-89319"
kind: "vulnerability"
aliases: ["CVE-2026-89319"]
title: "Go JWE decryptor trusts attacker-supplied plaintext length, enabling crashes and memory exhaustion"
severity: "medium"
cvss: 6.3
epss: 0.00207
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["go", "jwe", "package", "services-decrypting-untrusted-tokens", "thales"]
not_affected_if: ["no-untrusted-jwe-input"]
published_at: "2026-10-23T09:17:08+00:00"
first_seen_at: "2026-10-23T21:57:32+00:00"
updated_at: "2026-10-25T04:00:05+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89319", "first_seen_at": "2026-10-23T21:57:32+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-89319", "first_seen_at": "2026-10-24T07:15:51+00:00"}]
---

# Go JWE decryptor trusts attacker-supplied plaintext length, enabling crashes and memory exhaustion

The JweDirectDecryptorBlock.Decrypt function reads a 64-bit plaintext length from the _thales_aad protected-header field without validating it. A malformed token can crash the process with a panic or cause an unbounded memory allocation.

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

## How to check

- unknown

## Fix

- unknown

## Timeline

- 2026-10-23T21:57:32+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-89319
- 2026-10-24T07:15:51+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-89319

## From the sources

`JweDirectDecryptorBlock.Decrypt` read a 64-bit plaintext length from the `_thales_aad` protected-header field and used it without any validation. A truncated field panics `binary.BigEndian.Uint64`, an oversized value drives an unbounded allocation, and a value larger than the decrypted block panics with a slice-bounds error.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_