CVE-2026-47783Network attack vector

Username enumeration via SASL timing discrepancy

Published May 20, 2026 · Updated May 20, 2026

Observable timing discrepancy in Memcached memcached before 1.6.42 allows remote attackers to enumerate valid SASL usernames. sasl_server_userdb_checkpass exits its password-file loop when a username matches, making valid-name requests measurably faster than full scans. Exploitation requires network access to a server using SASL password-database authentication and repeated timing measurements; it reveals username validity, not passwords or cache data.

CVSS severity8.1
High
EPSS probability1.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Observable timing discrepancy in Memcached memcached before 1.6.42 allows remote attackers to enumerate valid SASL usernames. sasl_server_userdb_checkpass exits its password-file loop when a username matches, making valid-name requests measurably faster than full scans. Exploitation requires network access to a server using SASL password-database authentication and repeated timing measurements; it reveals username validity, not passwords or cache data.

The record

CVE
CVE-2026-47783
Published
May 20, 2026
Updated
May 20, 2026
Vendor
Memcached
Product
memcached
Classifications
CWE-208, T1087
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 20, 2026CVE publishedPublication date reported by the CVE source.
  2. May 20, 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=0 <1.6.42

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Memcached · memcachedversion=0 <1.6.42

Published CVSS scores

8.1MITRECVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

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 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-208Observable Timing 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

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Your stack

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