PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-47783 memcached CVE debrief

CVE-2026-47783 affects memcached versions before 1.6.42. In SASL password database authentication, sasl_server_userdb_checkpass exits its loop as soon as it finds a valid username, creating a timing side channel (CWE-208). NVD lists the issue as HIGH severity with CVSS 8.1, and the supplied record shows the item was still undergoing analysis at the time of publication.

Vendor
memcached
Product
Unknown
CVSS
HIGH 8.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-20
Original CVE updated
2026-09-18
Advisory published
2026-05-20
Advisory updated
2026-09-18

Who should care

Operators and security teams running memcached with SASL password database authentication should treat this as a priority fix, especially where the service is network-accessible or timing differences could be observed.

Technical summary

The vulnerability is a username-enumeration timing leak in memcached's SASL password database authentication path. Because the loop stops immediately when a valid username is found, response timing can vary based on whether a username exists, which aligns with CWE-208. The upstream remediation is associated with memcached 1.6.42, with NVD pointing to the fixing commit, the 1.6.41...1.6.42 comparison, and the 1.6.42 release notes.

Defensive priority

High. Upgrade memcached to 1.6.42 or later as soon as practical if SASL password database authentication is enabled, because the flaw can expose authentication metadata through timing differences without requiring user interaction.

Recommended defensive actions

  • Upgrade memcached to version 1.6.42 or later.
  • Review the upstream 1.6.42 release notes and the 1.6.41...1.6.42 comparison to confirm the fix is present in your build.
  • If SASL password database authentication is enabled, minimize exposure of the service to untrusted network observers.
  • Audit fleets and containers for older memcached binaries so patched versions are actually deployed everywhere.

Evidence notes

This debrief is based on the supplied CVE description and official references. The record states: memcached before 1.6.42, timing side channel in SASL password database authentication, and CWE-208. NVD metadata shows CVSS 3.1 vector AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H and status 'Undergoing Analysis' at the supplied modified time. Official references include the upstream commit d13f282b4bce33a9c33b8a1bbf07f12114160fed, the 1.6.41...1.6.42 comparison, and the 1.6.42 release notes.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-47783 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-47783

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-47783 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-47783

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.