CVE-2021-46876Network attack vector

Account enumeration via authentication response discrepancies

Published Mar 12, 2023 · Updated Mar 5, 2025

Observable discrepancy in Ibexa Kernel 6.13.0 through 6.13.8 and 7.5.0 through 7.5.15 allows remote attackers to enumerate accounts. The /user/sessions authentication path exposes whether a supplied username or email is valid through differences in response data or processing time. No authentication or user interaction is required, and the disclosed consequence is limited to learning which account identifiers are registered.

CVSS severity5.3
Medium
EPSS probability0.51%
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

Observable discrepancy in Ibexa Kernel 6.13.0 through 6.13.8 and 7.5.0 through 7.5.15 allows remote attackers to enumerate accounts. The /user/sessions authentication path exposes whether a supplied username or email is valid through differences in response data or processing time. No authentication or user interaction is required, and the disclosed consequence is limited to learning which account identifiers are registered.

The record

CVE
CVE-2021-46876
Published
Mar 12, 2023
Updated
Mar 5, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-203, T1087
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 12, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 5, 2025Record 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
5.3NIST NVDCVSS: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 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-203Observable Discrepancy
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

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