CVE-2026-27571MediumMicrosoft CVSS 5.9CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Microsoft security update for CVE-2026-27571

Published
February 27, 2026
Last Modified
—

🔗 CVE IDs covered (1)

📋 Microsoft's advisory

EchelonGraph does not copy Microsoft's advisory page: its FAQ and remediation text are not shown here. Read the advisory on https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-27571. This page also shows what EchelonGraph holds for CVE-2026-27571, with the description from its CVE record, which the CVE Numbering Authority that assigned the CVE wrote: for a CVE Microsoft assigned, often in the words of Microsoft's own advisory.

🎯 Affected products2

  • azl3 telegraf 1.31.0-12 on Azure Linux 3.0
  • cbl2 telegraf 1.29.4-18 on CBL Mariner 2.0

✅ Updates Microsoft lists: 2 updates

2 rows: one per KB article or update, update type and fixed build. Their details are on Microsoft's advisory.

KB articleUpdateFixed build
—Security Update1.29.4-19
—Security Update1.31.0-13

🧭 EchelonGraph on CVE-2026-27571

EchelonGraph score
7.5 HIGH
CISA KEV
Not listed
Fix status
A fix is available — apply it.

Description from the CVE record (CVE.org), as published by its numbering authority

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. The WebSockets handling of NATS messages handles compressed messages via the WebSockets negotiated compression. Prior to versions 2.11.2 and 2.12.3, the implementation bound the memory size of a NATS message but did not independently bound the memory consumption of the memory stream when constructing a NATS message which might then fail validation for size reasons. An attacker can use a compression bomb to cause excessive memory consumption, often resulting in the operating system terminating the server process. The use of compression is negotiated before authentication, so this does not require valid NATS credentials to exploit. The fix, present in versions 2.11.2 and 2.12.3, was to bounds the decompression to fail once the message was too large, instead of continuing on. The vulnerability only affects deployments which use WebSockets and which expose the network port to untrusted end-points.

Published by GitHub, Inc., the CVE Numbering Authority that assigned CVE-2026-27571, in its CVE record at CVE.org; reused under the CVE Program's Terms of Use (its licence and MITRE's copyright notice are in our Terms of Service).

🔗 References (2)