Quick answers
- Is CVE-2026-47784 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-47784 being exploited in the wild.
- How severe is CVE-2026-47784?
- High severity, with a CVSS score of 8.1, published 20 May 2026.
- Which products and versions are affected?
- Memcached before 1.6.42.
- Is there a fix for CVE-2026-47784?
- A patch was published on 2026-05-18: Release of version 1.6.42 fixing the issue. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-47784 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-47784?
- Check whether you run Memcached at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A timing side-channel vulnerability exists in the sasl_server_userdb_checkpass function of memcached before version 1.6.42. The implementation used the standard memcmp() function for username and password comparisons, which returns early upon encountering the first differing byte. Additionally, the authentication logic included an early break when a valid username was found in the password database. These behaviors create measurable timing discrepancies that a remote, unauthenticated attacker can exploit to perform timing attacks to determine valid usernames and eventually recover passwords. The fix, introduced in version 1.6.42, replaces memcmp with a constant-time comparison (safe_memcmp) and ensures the entire password file is scanned regardless of whether a match is found.
Affected products
- memcached memcached before 1.6.42
Timeline
- 2026-05-18: patched: Release of version 1.6.42 fixing the issue.
- 2026-05-20: advisory: CVE-2026-47784 published.