VulnerabilityPublished 17 Sep 2026

CVE-2026-75523: SteeltoeOSS security-advisories · Information Exposure

Affects SteeltoeOSS security-advisoriesSource CVE Database V5

Compare

Not known to be exploited · CVSS 5.9 Medium : upgrade to 4.3.0 when convenient.

Data as of 1 Nov 2026, 22:58 UTC

CVSS 3.1 base score

5.9Medium

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 38% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 4.3.0

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

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
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 17 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 1 Nov 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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 security-advisories and steeltoe.management.endpoint to 4.3.0.

Affected software

Product	Affected	Fixed in
SteeltoeOSSsecurity-advisories	Affected <4.3.0	Fixed in 4.3.0
NuGetsteeltoe.management.endpoint`pkg:nuget/steeltoe.management.endpoint`Other threats	Affected <4.3.0	Fixed in 4.3.0

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

AI-suggested

This vulnerability is fixed in SteeltoeOSS version 4.3.0. Users should upgrade to version 4.3.0 or later to remediate the issue. If upgrading is not immediately possible, disabling the Management:Endpoints:HttpExchanges:IncludeQueryString setting will prevent query string data from being included in the endpoint response, mitigating the exposure. Review and restrict access to DEBUG logs to prevent sensitive data disclosure through logging.

Description

Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. Prior to 4.3.0, the Steeltoe.Management.Endpoint /actuator/httpexchanges endpoint passes recorded request URIs through MaskedUri, which masks URI user information but does not inspect query strings. When Management:Endpoints:HttpExchanges:IncludeQueryString is enabled, the HttpExchangeRequest response can disclose OAuth tokens, password-reset tokens, signed-URL signatures, API keys, and other query-string secrets from prior traffic to a caller that can reach the explicitly exposed endpoint. The Steeltoe.Management.Endpoint.Actuators.HttpExchanges DEBUG logger also records these URIs, creating a second disclosure channel for users with log access. This issue is fixed in version 4.3.0.

Impact

An attacker who can access the /actuator/httpexchanges endpoint with IncludeQueryString enabled may obtain sensitive information such as OAuth tokens, password-reset tokens, signed-URL signatures, and API keys from previous HTTP requests. This exposure can lead to unauthorized access or misuse of these credentials. Additionally, sensitive data may be exposed through DEBUG logs accessible to users with log access privileges. The vulnerability does not affect system integrity or availability but compromises confidentiality.

Summary

SteeltoeOSS versions before 4.3.0 have a vulnerability in the Steeltoe.Management.Endpoint /actuator/httpexchanges endpoint. While the MaskedUri function masks user information in URIs, it does not inspect or mask query string parameters. If the Management:Endpoints:HttpExchanges:IncludeQueryString setting is enabled, sensitive data contained in query strings from prior HTTP traffic can be disclosed to any caller able to access this endpoint. Furthermore, the DEBUG logger records these URIs, potentially exposing sensitive tokens and keys to users with log access. This vulnerability is addressed in SteeltoeOSS version 4.3.0.

CWE-200Exposure of Sensitive Information to an Unauthorized Actor (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #20OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
Subverting Environment Variable Values (opens in a new tab)
ICMP Echo Request Ping (opens in a new tab)
TCP SYN Scan (opens in a new tab)
Enumerate Mail Exchange (MX) Records (opens in a new tab)
DNS Zone Transfers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 17 Sep 2026, 16:02 UTC

WeaknessesCWE-200

Technical details

References

Community reviews

Related threats