CVE-2023-49278Network attack vector

Username enumeration via password-reset timing differences

Published Dec 12, 2023 · Updated Oct 8, 2024

Username enumeration in affected Umbraco CMS releases allows remote attackers to identify valid backoffice accounts via password-reset requests. The forgot-password handler takes longer for registered email addresses because it performs additional internal processing, creating a timing oracle. No authentication or user interaction is required, but exploitation requires repeated timing comparisons and discloses account identifiers rather than passwords.

CVSS severity5.3
Medium
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Username enumeration in affected Umbraco CMS releases allows remote attackers to identify valid backoffice accounts via password-reset requests. The forgot-password handler takes longer for registered email addresses because it performs additional internal processing, creating a timing oracle. No authentication or user interaction is required, but exploitation requires repeated timing comparisons and discloses account identifiers rather than passwords.

The record

CVE
CVE-2023-49278
Published
Dec 12, 2023
Updated
Oct 8, 2024
Vendor
Umbraco
Product
Umbraco CMS
Classifications
CWE-200, CWE-307, T1087
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 12, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 8, 2024Record 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=>= 11.0.0-rc1, < 12.3.4
  2. Affected versionversion=>= 8.0.0, < 8.18.10
  3. Affected versionversion=>= 9.0.0-rc001, < 10.8.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Umbraco · Umbraco CMSversion=>= 11.0.0-rc1, < 12.3.4; version=>= 8.0.0, < 8.18.10; version=>= 9.0.0-rc001, < 10.8.1

Published CVSS scores

5.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
5.3NISTCVSS: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-200Exposure of Sensitive Information to an Unauthorized Actor
CWE-307Improper Restriction of Excessive Authentication Attempts
T1087Account Discovery

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

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Your stack

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