CVE-2026-48780Network attack vector

Invite-only access via encoded-word email validation

Published Jun 16, 2026 · Updated Jun 16, 2026

Authentication bypass in Forem before commit a2ab6d4 allows remote attackers to access invite-only deployments using a crafted email address. The User email model accepts RFC 2047 encoded-word syntax, so domain checks see an allowed suffix while mail decoding changes the effective recipient address. Unauthenticated registration or magic-link access and an invite-only deployment with domain restrictions are required; successful exploitation creates an admitted account.

CVSS severity8.2
High
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Forem before commit a2ab6d4 allows remote attackers to access invite-only deployments using a crafted email address. The User email model accepts RFC 2047 encoded-word syntax, so domain checks see an allowed suffix while mail decoding changes the effective recipient address. Unauthenticated registration or magic-link access and an invite-only deployment with domain restrictions are required; successful exploitation creates an admitted account.

The record

CVE
CVE-2026-48780
Published
Jun 16, 2026
Updated
Jun 16, 2026
Vendor
Forem
Product
Forem
Classifications
CWE-287, T1136
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< a2ab6d4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Forem · Foremversion=< a2ab6d4

Published CVSS scores

8.2GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
T1136Create Account

Public exploit references

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Technologies

Your stack

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Your stack

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