CVE-2026-27454Network attack vector

Hidden revision disclosure via unchecked post rollback

Published Mar 19, 2026 · Updated Mar 19, 2026

Missing authorization in Discourse before 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 allows remote attackers to read hidden post revisions. The display_post method passes an attacker-selected version to post.revert_to without first verifying revision visibility or edit-history permission. No account is required; an attacker who identifies a post ID can enumerate versions and recover staff-hidden revision content without write access.

CVSS severity5.3
Medium
EPSS probability0.89%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Missing authorization in Discourse before 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 allows remote attackers to read hidden post revisions. The display_post method passes an attacker-selected version to post.revert_to without first verifying revision visibility or edit-history permission. No account is required; an attacker who identifies a post ID can enumerate versions and recover staff-hidden revision content without write access.

The record

CVE
CVE-2026-27454
Published
Mar 19, 2026
Updated
Mar 19, 2026
Vendor
Discourse
Product
Discourse
Classifications
CWE-862, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=>= 2026.1.0-latest, < 2026.1.2
  2. Affected versionversion=>= 2026.2.0-latest, < 2026.2.1
  3. Affected versionversion== 2026.3.0-latest

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Discourse · Discourseversion=>= 2026.1.0-latest, < 2026.1.2; version=>= 2026.2.0-latest, < 2026.2.1; version== 2026.3.0-latest

Published CVSS scores

5.3GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-862Missing Authorization
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo