VulnerabilityPublished 13 Nov 2026

CVE-2026-19194: HashiCorp Shared library · Improper Handling of Case Sensitivity

Affects HashiCorp Shared librarySource CVE Database V5

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Not known to be exploited · CVSS 5.9 Medium : upgrade to 0.14.0 when convenient.

Data as of 13 Nov 2026, 21:47 UTC

CVSS 3.1 base score

5.9Medium

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

Thin evidence

One scorer or none

CVSS scores by source
CNA (HashiCorp)	CVSS 3.1	5.9

Patch: Available – fixed in 0.14.0

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

Attack Vector: Network
Attack Complexity: High
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
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: 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: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to 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 13 Nov 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 13 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 HashiCorp Shared library to 0.14.0.

Affected software

Product	Affected	Fixed in
HashiCorpShared library	Affected <0.14.0	Fixed in 0.14.0
GitHubShared library`pkg:github/Shared library`Other threats	Affected <0.14.0	Fixed in 0.14.0

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

AI-suggested

Upgrade the HashiCorp cap JWT validation library to version 0.14.0 or later, where this vulnerability is fixed. No other mitigation is indicated or required according to the vendor advisory.

Description

The HashiCorp cap JWT validation library before version 0.14.0 is vulnerable to a claims validation bypass that may cause downstream applications to make authorization decisions using claim values different from those validated. Exploitation requires attacker-controlled claims in a JWT signed by a key trusted by the application. This vulnerability (CVE-2026-19194) is fixed in cap 0.14.0.

Impact

Successful exploitation can lead to authorization bypass in applications relying on the vulnerable library for JWT claims validation. This may allow attackers to gain unauthorized access or privileges by presenting JWTs with manipulated claims that are not properly validated due to case sensitivity issues. The CVSS score of 5.9 reflects a medium severity with high impact on confidentiality and integrity but requires high privileges and has a high attack complexity.

Summary

The HashiCorp cap JWT validation library versions prior to 0.14.0 contain a CWE-178 improper handling of case sensitivity vulnerability. This flaw allows an attacker who can control JWT claims signed by a trusted key to bypass claims validation, potentially causing downstream applications to authorize actions based on manipulated claim values. The vulnerability is addressed in cap version 0.14.0.

CWE-178Improper Handling of Case Sensitivity (opens in a new tab)
Base weakness
The product does not properly account for differences in case sensitivity when accessing or determining the properties of a resource, leading to inconsistent results.
Architecture and Design · Input Validation
Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Implementation · Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174).
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

discuss.hashicorp.com/t/hcsec-2026-60-cap-jwt-claims-validation-bypass-using-non-canonical-claim-names/78258 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 13 Nov 2026, 21:47 UTC

WeaknessesCWE-178

Technical details

References

Community reviews

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