Cyber Resilience

CVE-2026-31049

Published
14 April 2026
Modified
27 April 2026
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0066 48th percentile
Risk Priority 72 floored blend · peak EPSS

Summary

CVE-2026-31049 is a critical-severity Improper Neutralization of Formula Elements in a CSV File (CWE-1236) vulnerability in Hostbillapp (inferred from references). Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique User Execution (T1204); ranked at the 48th 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 SI-15 (Information Output Filtering) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-31049 is a critical vulnerability (CVSS 9.8, CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) affecting Hostbill versions 2025-11-24 and 2025-12-01. The issue, classified under CWE-1236, enables a remote attacker to execute arbitrary code and escalate privileges via the CSV registration field. Published on 2026-04-14, it represents a severe flaw in the application's handling of CSV imports during registration processes.

Any remote attacker with network access can exploit this vulnerability due to its low attack complexity, lack of required privileges or user interaction, and unchanged impact scope. Exploitation through the CSV registration field allows achievement of high impacts on confidentiality, integrity, and availability, culminating in arbitrary code execution and privilege escalation on the affected Hostbill instance.

Vendor-provided resources detail potential mitigations, including a security advisory at https://blog.hostbillapp.com/2025/12/03/hostbill-security-advisory/, changelog at https://hostbillapp.com/changelog, and release notes for versions 11-27-2025 and 12-01-2025 at https://hostbillapp.com/release-notes/11-27-2025.html and https://hostbillapp.com/release-notes/12-01-2025.html. A GitHub repository at https://github.com/Muhammad5235/HostBill-CVEs-2025/blob/main/Missing%20Server-Side%20Validation/Registration%20fields%20%26%20Import%20Csv documents the missing server-side validation underlying the flaw.

EU & UK References

Vulnerability Data

An issue in Hostbill v.2025-11-24 and 2025-12-01 allows a remote attacker to execute arbitrary code and escalate privileges via the CSV registration field

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1204 User Execution Execution
An adversary may rely upon specific actions by a user in order to gain execution.
T1204.002 Malicious File Execution
An adversary may rely upon a user opening a malicious file in order to gain execution.
T1566 Phishing Initial Access
Adversaries may send phishing messages to gain access to victim systems.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-45084Shared CWE-1236
CVE-2024-47485Shared CWE-1236
CVE-2025-54752Shared CWE-1236
CVE-2026-23873Shared CWE-1236
CVE-2023-29918Shared CWE-1236
CVE-2023-23796Shared CWE-1236
CVE-2025-1421Shared CWE-1236
CVE-2025-66834Shared CWE-1236
CVE-2026-41073Shared CWE-1236
CVE-2025-52612Shared CWE-1236

Affected Assets

Hostbillapp
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.2.10

Mitigating Controls (NIST 800-53 r5) AI

Output filtering/validation directly stops unneutralized formula elements from being written into CSV files.

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.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require output neutralization for untrusted CSV content to block formula injection.

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.

finds

Security testing in development can detect formula injection but does not itself implement the mitigation.

prevents

Secure SDLC mandates input validation and output encoding that directly prevents formula injection in CSV exports.

prevents

Application security requirements include rules for safe CSV generation and handling of untrusted data.

prevents

Secure architecture principles encourage safe data export design but do not specifically address CSV formula neutralization.

prevents

Secure coding standards explicitly require neutralization of special characters when writing CSV files.

References