VulnerabilityPublished 18 Jun 2025

CVE-2025-49015: couchbase.netclient · CVE-2025-49015 is a

Affects couchbase.netclientSource CVE Database V5

Not known to be exploited · CVSS 4.9 Medium : upgrade to 3.7.1 when convenient.

Data as of 26 Oct 2026, 11:07 UTC

CVSS 3.1 base score

4.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.7.1

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Jun 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade couchbase.netclient to 3.7.1.

Affected software

Product	Affected	Fixed in
NuGetcouchbase.netclient`pkg:nuget/couchbase.netclient`Other threats	Affected <3.7.1	Fixed in 3.7.1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available in Couchbase .NET SDK version 3.7.1 and later. Users should upgrade to version 3.7.1 or newer to ensure proper hostname verification is enabled by default. No other mitigations are specified.

Description

CVE-2025-49015 is a vulnerability in the Couchbase .NET SDK client library versions before 3.7.1. The issue involves improper hostname verification for TLS certificates, where the SDK incorrectly uses IP addresses instead of hostnames due to a misconfigured default setting. This flaw could allow an attacker to bypass hostname verification during TLS connections.

Impact

This vulnerability impacts the confidentiality of communications by potentially allowing man-in-the-middle attacks where an attacker could present a valid TLS certificate for a different hostname or IP address. The CVSS score of 4.9 (medium severity) reflects a network attack vector with low complexity but requiring high privileges. There is no impact on integrity or availability reported.

Summary

The Couchbase .NET SDK prior to version 3.7.1 does not properly enforce hostname verification for TLS certificates. The SDK was configured by default to use IP addresses instead of hostnames, which undermines the security guarantees of TLS hostname verification. This vulnerability is identified as CWE-297 (Improper Validation of Certificate with Host Mismatch).

CWE-297Improper Validation of Certificate with Host Mismatch (opens in a new tab)
Variant weaknessLikelihood of exploit: HighOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The product communicates with a host that provides a certificate, but the product does not properly ensure that the certificate is actually associated with that host.
Architecture and Design
Fully check the hostname of the certificate and provide the user with adequate information about the nature of the problem and how to proceed.
Implementation
If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V1.14.1 (opens in a new tab)
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 19 Oct 2026, 22:32 UTC

WeaknessesCWE-297

Technical details

References

Community reviews

Related threats