CVE-2025-30347Network attack vector

Memory disclosure via incorrect range buffer bounds

Published Mar 21, 2025 · Updated Mar 21, 2025

Out-of-bounds read in MSE4 in Varnish Software Varnish Enterprise 6.0.13r2 through 6.0.13r12 allows remote attackers to read server memory. An incorrect boundary calculation for range offsets inside an ephemeral object's buffer sends bytes beyond that buffer as response data. Exposure requires the non-default -s mse4 configuration, and disclosed bytes can contain adjacent cached content or internal data such as TLS certificates.

CVSS severity4.0
Medium
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Out-of-bounds read in MSE4 in Varnish Software Varnish Enterprise 6.0.13r2 through 6.0.13r12 allows remote attackers to read server memory. An incorrect boundary calculation for range offsets inside an ephemeral object's buffer sends bytes beyond that buffer as response data. Exposure requires the non-default -s mse4 configuration, and disclosed bytes can contain adjacent cached content or internal data such as TLS certificates.

The record

CVE
CVE-2025-30347
Published
Mar 21, 2025
Updated
Mar 21, 2025
Vendor
Varnish Software
Product
Varnish Enterprise
Classifications
CWE-125, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 21, 2025CVE publishedPublication date reported by the CVE source.
  2. Mar 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6 <6.0.13r13

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Varnish Software · Varnish Enterpriseversion=6 <6.0.13r13

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
4.0MITRECVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-125Out-of-bounds Read
T1190Exploit Public-Facing Application

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo