---
id: CVE-2026-48990
title: >-
  joserfc: joserfc: Resource exhaustion via oversized JSON Web Signature (JWS)
  payloads (CVE-2026-48990)
summary: >-
  A flaw was found in joserfc, a Python library for JSON Object Signing and
  Encryption (JOSE). This vulnerability allows a remote attacker to cause
  resource exhaustion, leading to a Denial of Service (DoS), by sending
  oversized JSON Web Sign…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cvssSource: vendor
cwe:
  - CWE-770
  - CWE-400
vendor: Red Hat
product: Red Hat Ansible Automation Platform 2.6
affected:
  - ansible_automation_platform 2.6
  - ansible_automation_platform 2.7
  - hardened_images
  - migration_toolkit_for_applications 8.2
patched:
  - ansible_automation_platform 2.6
  - ansible_automation_platform 2.7
  - hardened_images
  - migration_toolkit_for_applications 8.2
published: '2026-06-17'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T11:23:26+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48990.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48990.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-48990'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2490168'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-48990'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-48990'
  - url: 'https://github.com/authlib/joserfc/releases/tag/1.6.7'
  - url: 'https://github.com/authlib/joserfc/security/advisories/GHSA-wphv-vfrh-23q5'
  - url: 'https://access.redhat.com/errata/RHSA-2026:50479'
  - url: 'https://access.redhat.com/errata/RHSA-2026:50340'
  - url: 'https://access.redhat.com/errata/RHSA-2026:25039'
  - url: 'https://access.redhat.com/errata/RHSA-2026:43038'
  - url: 'https://github.com/authlib/joserfc'
  - url: 'https://github.com/advisories/GHSA-wphv-vfrh-23q5'
tags:
  - csaf
  - vex
  - red-hat
  - osv
  - pip
  - ghsa
epss: 0.00163
epssPercentile: 0.05419
aliases:
  - GHSA-wphv-vfrh-23q5
  - PYSEC-2026-2530
ecosystem: pip
ingestedAt: '2026-06-29T13:24:35.253Z'
---

## Overview

A flaw was found in joserfc, a Python library for JSON Object Signing and Encryption (JOSE). This vulnerability allows a remote attacker to cause resource exhaustion, leading to a Denial of Service (DoS), by sending oversized JSON Web Signature (JWS) payloads. The library fails to apply size limits, specifically JWSRegistry.max_payload_length, when processing RFC7797 b64=false JWS payloads.

## Vendor advisories

- **RHSA-2026:50479** · Red Hat · fixed in: Red Hat Ansible Automation Platform 2.6 · released 2026-08-04 · [advisory](https://access.redhat.com/errata/RHSA-2026:50479)
- **RHSA-2026:50340** · Red Hat · fixed in: Red Hat Ansible Automation Platform 2.7 · released 2026-08-04 · [advisory](https://access.redhat.com/errata/RHSA-2026:50340)
- **RHSA-2026:25039** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-06-10 · [advisory](https://access.redhat.com/errata/RHSA-2026:25039)
- **RHSA-2026:43038** · Red Hat · fixed in: Red Hat Migration Toolkit for Applications 8.2 · released 2026-07-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:43038)

**joserfc: joserfc: Resource exhaustion via oversized JSON Web Signature (JWS) payloads** — rated Moderate by Red Hat. Released 2026-06-17, updated 2026-10-16.

Fixed:

- Red Hat Ansible Automation Platform 2.6
- Red Hat Ansible Automation Platform 2.7
- Red Hat Hardened Images
- Red Hat Migration Toolkit for Applications 8.2

Not affected:

- Red Hat Ansible Automation Platform 2.6
- Red Hat Ansible Automation Platform 2.7
- Red Hat Migration Toolkit for Applications 8.2
- Red Hat Satellite 6

## Remediation

Before applying this update, make sure all previously released errata relevant to your system have been applied.
For details on how to apply this update, refer to:
https://docs.redhat.com/en/documentation/red_hat_ansible_automation_platform/2.6#Upgrade https://access.redhat.com/errata/RHSA-2026:50479
Before applying this update, make sure all previously released errata relevant to your system have been applied.
For details on how to apply this update, refer to:
https://docs.redhat.com/en/documentation/red_hat_ansible_automation_platform/2.7#Upgrade https://access.redhat.com/errata/RHSA-2026:50340
For details on how to apply this update, which includes the changes described in this advisory, refer to:
https://images.redhat.com/ https://access.redhat.com/errata/RHSA-2026:25039

Workarounds / mitigations:

- The risk can be mitigated by rejecting oversized serialized JWS inputs before they reach joserfc and enforcing strict request/body size limits at the application or reverse-proxy layer.

## Package advisory (CVE-2026-48990)

Affected packages:

- `joserfc >= 1.3.4, < 1.6.7`

Patched in:

- `joserfc 1.6.7`

Source: https://osv.dev/vulnerability/GHSA-wphv-vfrh-23q5