---
id: CVE-2026-90679
title: >-
  Forgejo 13.0.0 through 16.0.4, when "[federation] ENABLED = true" is set, has
  a spoofing issue that affects identity integrity but does not allow account
  takeover or content modification
summary: >-
  Forgejo 13.0.0 through 16.0.4, when "[federation] ENABLED = true" is set, has
  a spoofing issue that affects identity integrity but does not allow account
  takeover or content modification. It does not verify that the HTTP Signature
  on an …
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N'
cwe:
  - CWE-348
vendor: Forgejo
product: Forgejo
affected:
  - Forgejo >= 13.0.0 <= 16.0.4
published: '2026-09-13'
updated: '2026-09-22'
sourceUpdated: '2026-09-22T20:00:03.713'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90679'
references:
  - url: 'https://codeberg.org/forgejo/forgejo/issues/14271#issuecomment-22548004'
    label: cve@mitre.org
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-90679.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-90679'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-90679'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00162
epssPercentile: 0.05877
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-15T17:17:23.327706Z'
ingestedAt: '2026-09-14T15:23:07.477Z'
---

## Overview

Forgejo 13.0.0 through 16.0.4, when "[federation] ENABLED = true" is set, has a spoofing issue that affects identity integrity but does not allow account takeover or content modification. It does not verify that the HTTP Signature on an incoming ActivityPub activity was produced by the key belonging to the actor named in the activity body. The signature verification in routers/api/v1/activitypub/reqsignature.go validates the request signature, but the inbox activity handlers subsequently read the acting identity from the attacker-controlled JSON body without binding it to the verified signing key. Additionally, the signed Digest header is not recomputed against the received request body. A remote attacker who hosts a single valid ActivityPub actor and keypair can therefore submit signature-valid activities attributed to any actor identity they name.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-90679.json)