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Fencer Vulns
medium 5.3

CVE-2026-90698 json

memcached mcmc Tokenizer proto_text.c try_read_command_asciiauth out-of-bounds

published 2026-09-14 56 d ago modified 2026-09-15 55 d ago also EUVD-2026-77330

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 58%
public exploits
0
none known

Summary

A security flaw has been discovered in memcached 1.6.41/1.6.42/1.6.43. This vulnerability affects the function try_read_command_asciiauth of the file proto_text.c of the component mcmc Tokenizer. The manipulation results in out-of-bounds read. It is possible to launch the attack remotely. The exploit has been released to the public and may be used for attacks. Upgrading to version 1.6.44 is able to resolve this issue. The patch is identified as af05c9302bba508b736c3da1d5670f63fe8b7db4. You should upgrade the affected component.

Patch / fix

  • n/a memcached 1.6.44
  • memcached Debian 14 1.6.45-1

debian advisories DEBIAN-CVE-2026-90698

  • memcached Ubuntu 22.04 LTS 1.6.14-1ubuntu0.3
  • memcached Ubuntu 24.04 LTS 1.6.24-1ubuntu0.3
  • memcached Ubuntu 26.04 LTS 1.6.40-1ubuntu0.3

ubuntu advisories UBUNTU-CVE-2026-90698

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • memcached hummingbird 1 1.6.45-1.hum1
  • memcached-selinux hummingbird 1 1.6.45-1.hum1

red hat advisories RHSA-2026:63224

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-90698 updated cvss 5.3

memcached: memcached: Denial of Service due to out-of-bounds read

  • Red Hat Hardened Images memcached 1.6.45-1.hum1, memcached-selinux 1.6.45-1.hum1
    fixed: vendor fix RHSA-2026:63224
  • Red Hat Enterprise Linux 6 memcached Red Hat Enterprise Linux 7 memcached Red Hat Enterprise Linux 8 memcached Red Hat Enterprise Linux 9 memcached, rhel9/memcached, memcached-selinux Red Hat Enterprise Linux 10 memcached, rhel10/memcached Red Hat OpenStack Platform 13 (Queens) memcached
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
55 d ago

Exploit prediction

0.86% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • protectiv.ph https://protectiv.ph/research/memcached-asciiauth-empty-line-dos referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C
CNA 3.0 5.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C
CNA 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P/E:POC/RL:OF/RC:C
CNA 4.0 5.5 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CNA 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

  • n/a memcached

Classification

Weakness
  • CWE-125 Out-of-bounds Read
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.