Cyber Resilience

CVE-2026-42341

Access Control

Published
06 July 2026
Modified
07 July 2026
CVSS Score v4 9.2
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0027 20th percentile
Risk Priority 44 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-42341 is a critical-severity Missing Authentication for Critical Function (CWE-306) vulnerability. Its CVSS base score is 9.2 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique ARP Cache Poisoning (T1557.002); ranked at the 20th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-14 (Permitted Actions Without Identification or Authentication) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

FOSSBilling is a free, open-source billing and client management system. Versions 0.6.0 through 0.7.2 have an unauthenticated payment bypass vulnerability in FOSSBilling's IPN callback endpoint. When the Custom payment adapter is enabled, an attacker can mark any unpaid invoice as…

more

paid and credit the associated client account without making an actual payment, by sending a single crafted HTTP request. Version 0.8.0 patches the issue. Some workarounds are available. Disable the Custom payment gateway if not actively needed and/or restrict access to `/ipn.php` at the web server level (e.g., via IP allowlisting), noting that this may interfere with legitimate payment callback processing.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1557.002 ARP Cache Poisoning Credential Access
Adversaries may poison Address Resolution Protocol (ARP) caches to position themselves between the communication of two or more networked devices.
T1133 External Remote Services Persistence
Adversaries may leverage external-facing remote services to initially access and/or persist within a network.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1528 Steal Application Access Token Credential Access
Adversaries can steal application access tokens as a means of acquiring credentials to access remote systems and resources.
T1550.004 Web Session Cookie Lateral Movement
Adversaries can use stolen session cookies to authenticate to web applications and services.
T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-60765Shared CWE-306, CWE-346
CVE-2024-32764Shared CWE-306, CWE-346
CVE-2026-59971Shared CWE-306, CWE-346
CVE-2026-46685Shared CWE-306, CWE-346
CVE-2026-46728Shared CWE-346
CVE-2023-27745Shared CWE-346
CVE-2024-13068Shared CWE-346
CVE-2026-66322Shared CWE-346
CVE-2026-53499Shared CWE-346
CVE-2026-12304Shared CWE-346

Affected Assets

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 9 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.2.3
  • V6.4.4
  • V10.4.16
  • V12.1.3

Mitigating Controls (NIST 800-53 r5) AI

Directly mandates unique identification and authentication of users before access to functions requiring identity.

Extends the same authentication requirement to non-organizational users accessing critical functionality.

Requires authentication of services before they can invoke or expose critical functions.

Explicitly identifies and limits actions permitted without authentication, preventing critical functions from being exposed.

Information flow enforcement directly requires validating the source of data before allowing transmission or receipt.

Device identification and authentication mandates verifying the source before establishing connections.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

ID.AM-03 partial match
prevents

Documenting authorized flows supports origin validation by defining expected sources.

PR.AA-01 partial match
prevents

Managing identities and credentials is a prerequisite for authentication but does not itself enforce it on critical functions.

PR.AA-03 partial match
prevents

Directly requires authentication of users/services/hardware, which eliminates missing authentication for critical functions.

PR.AA-04 partial match
prevents

Verifying identity assertions enforces origin validation for conveyed claims.

PR.AA-05 partial match
prevents

Defining and enforcing authorizations assumes prior authentication and therefore only partially mitigates the absence of authentication.

PR.IR-01 partial match
prevents

Protecting networks from unauthorized access can be undermined by missing authentication but does not address the root authentication gap.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Mandating authentication requirements for critical functions at the requirements-gathering stage ensures that essential operations are not left unprotected by missing login or verification mechanisms.

mitigates

Network security controls enforce origin validation at network boundaries.

mitigates

Mandating authentication for network services and critical functions stops attackers from invoking sensitive operations without credentials, closing gaps where authentication is absent for important capabilities.

mitigates

Network segregation reduces exposure but does not directly validate origins.

prevents

Application security requirements explicitly call for origin validation of inputs and communications.

prevents

Security engineering principles insist on authentication and authorization for every critical function, eliminating entry points that lack any access control mechanism.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (higher-evidence rows only; rows rated `none` are excluded).

Oracle Linux 8 (4 rules)
  • V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. prevents CWE-346
  • V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-346
  • V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-306, CWE-346
RHEL 7 (2 rules)
  • V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. prevents CWE-306
  • V-237635 The Red Hat Enterprise Linux operating system must require re-authentication when using the "sudo" command. prevents CWE-306
RHEL 8 (2 rules)
  • V-230492 RHEL 8 must not have the rsh-server package installed. prevents CWE-306
  • V-237643 RHEL 8 must require re-authentication when using the "sudo" command. prevents CWE-306

References