VulnerabilityPublished 24 Mar 2026

CVE-2026-21790: HCLSoftware Traveler · Origin Validation Error

Affects HCLSoftware TravelerSource CVE Database V5

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Not known to be exploited · CVSS 6.3 Medium : upgrade to 14.5.1.0 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

6.3Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 14.5.1.0

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

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

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: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 24 Mar 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 30 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.
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 HCLSoftware Traveler to 14.5.1.0.

Affected software

Product	Affected	Fixed in
HCLSoftwareTraveler	Affected <14.5.1.0	Fixed in 14.5.1.0

AI-suggested

If you cannot patch yet, administrators should implement strict HTTP header validation rules at the web server or application gateway level to enforce proper origin checks and reject suspicious or malformed headers. Network segmentation and strict access controls should limit who can authenticate to the Traveler service, reducing the pool of potential attackers. Monitoring and logging of authentication attempts and HTTP header anomalies can help detect exploitation attempts early. Additionally, organizations should review and tighten any custom authentication or authorization mechanisms integrated with Traveler to ensure they do not rely solely on HTTP headers for security decisions. Security teams should also conduct regular vulnerability assessments and penetration testing focused on web application security controls to identify similar weaknesses proactively.

Description

HCL Traveler is susceptible to a weak default HTTP header validation vulnerability, which could allow an attacker to bypass additional authentication checks.

Impact

The vulnerability could allow attackers to bypass additional authentication checks, potentially leading to unauthorized access to sensitive email and collaboration data managed by HCL Traveler. This could compromise confidentiality by exposing private communications, integrity by allowing unauthorized changes to data, and availability if attackers disrupt services. Although exploitation requires some level of authenticated access, the ability to bypass further authentication layers increases the risk of privilege escalation or lateral movement within an organization’s network. Organizations relying on HCL Traveler for mobile email access, especially those handling sensitive or regulated data, face increased risk of data breaches or insider threat exploitation. The lack of known exploits in the wild reduces immediate risk but does not eliminate the potential for future attacks, especially if threat actors develop proof-of-concept exploits. The medium severity rating suggests a moderate impact, but in high-security environments, even this level of vulnerability warrants prompt remediation.

CWE-346Origin Validation Error (opens in a new tab)
Class weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The product does not properly verify that the source of data or communication is valid.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V14.5.2 (opens in a new tab)
V14.5.3 (opens in a new tab)
V1.4.4 (opens in a new tab)
Attack patterns
JSON Hijacking (aka JavaScript Hijacking) (opens in a new tab)
Cache Poisoning (opens in a new tab)
DNS Cache Poisoning (opens in a new tab)
Exploit Script-Based APIs (opens in a new tab)
Application API Message Manipulation via Man-in-the-Middle (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

support.hcl-software.com/csm?id=kb_article&sysparm_article=KB0129139 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 24 Mar 2026, 20:48 UTC

WeaknessesCWE-346

Technical details

References

Community reviews

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