Cyber Resilience

CVE-2026-46386

RCE

Published
26 June 2026
Modified
29 June 2026
CVSS Score v3.1 9.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0027 19th percentile
Risk Priority 67 floored blend · peak EPSS

Summary

CVE-2026-46386 is a critical-severity Deserialization of Untrusted Data (CWE-502) vulnerability. Its CVSS base score is 9.9 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Default Accounts (T1078.001); ranked at the 19th 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 CM-2 (Baseline Configuration) and CM-6 (Configuration Settings) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

OpenProject is open-source, web-based project management software. Prior to , the official openproject/openproject Docker image ships ENV SECRET_KEY_BASE=OVERWRITE_ME as the default Rails master key. Combined with cookies_serializer = :marshal, this gives any logged-in user a deterministic Marshal-deserialization path reachable via…

more

the /my/two_factor_devices cookie reader This vulnerability is fixed in .

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1078.001 Default Accounts Stealth
Adversaries may obtain and abuse credentials of a default account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
T1552 Unsecured Credentials Credential Access
Adversaries may search compromised systems to find and obtain insecurely stored credentials.
T1552.001 Credentials In Files Credential Access
Adversaries may search local file systems and remote file shares for files containing insecurely stored credentials.
T1078 Valid Accounts Stealth
Adversaries may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
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.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-6448Shared CWE-1188, CWE-798
CVE-2026-44825Shared CWE-1188, CWE-798
CVE-2026-33072Shared CWE-1188, CWE-798
CVE-2026-36616Shared CWE-1188, CWE-798
CVE-2026-65313Shared CWE-1392, CWE-798
CVE-2023-30801Shared CWE-1392, CWE-798
CVE-2025-58744Shared CWE-1392, CWE-798
CVE-2025-35452Shared CWE-1392, CWE-798
CVE-2023-27573Shared CWE-1392, CWE-798
CVE-2026-45039Shared CWE-1392, CWE-798

Affected Assets

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 13 hardening rules · 7 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V14.3.2
  • V13.2.1
  • V6.3.2
  • V11.3.1

Mitigating Controls (NIST 800-53 r5) AI

Baseline configuration directly requires documenting and maintaining secure initial settings instead of insecure defaults.

Configuration settings mandate the most restrictive values be applied at initialization, eliminating reliance on insecure factory defaults.

Authenticator management requires secure distribution and handling of credentials, structurally discouraging hard-coded values.

Vulnerability scanning can discover default credentials after deployment but does not stop their introduction.

Developer testing and evaluation can uncover deserialization flaws before deployment.

Cryptographic key management mandates proper establishment and handling instead of embedding keys in code.

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-01 full match
prevents

Hardened baselines and configuration management directly replace insecure defaults with secure settings.

PR.AA-01 mostly match
prevents

Credential management processes directly require replacing or disabling default passwords and keys.

PR.PS-06 mostly match
prevents

Secure development practices include designing products with secure defaults rather than insecure ones.

ID.RA-09 partial match
prevents

Pre-acquisition integrity checks can reject products known to ship with insecure defaults.

PR.AA-03 partial match
prevents

Authentication policies can enforce non-default credential strength but do not explicitly address initial deployment defaults.

PR.AA-02 none match
prevents

PR.AA-02 addresses human identity proofing and per-person credential issuance at enrollment; it has no bearing on whether developers embed static credentials in software.

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 includes validation of deserialization routines and the use of untrusted data, reducing the likelihood that unsafe object reconstruction will be deployed.

prevents

Mandating secure baseline templates and immediate replacement of vendor defaults directly stops systems from being deployed with insecure factory settings that attackers can exploit.

prevents

Education on secure configuration practices discourages technical staff from embedding or relying on hard-coded credentials in systems and applications.

mitigates

Secure key-generation, distribution and storage procedures reduce the likelihood that hard-coded or default cryptographic keys will be introduced or left unprotected.

prevents

Requiring vetted libraries, regular updates and SAST before release reduces the likelihood that deserialization logic will accept and act on attacker-controlled serialized objects.

prevents

Contractual requirements for secure coding practices and evidence of testing make it less likely that hard-coded credentials will be introduced or remain undetected in delivered code.

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` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248823 OL 8 must not have the telnet-server package installed. prevents CWE-1188
RHEL 7 (1 rule)
  • V-204627 SNMP community strings on the Red Hat Enterprise Linux operating system must be changed from the default. prevents CWE-1188
Ubuntu 22.04 (1 rule)
  • V-260529 Ubuntu 22.04 LTS must be configured so that remote X connections are disabled, unless to fulfill documented and validated mission requirements. prevents CWE-1188
Ubuntu 24.04 (1 rule)
  • V-270708 Ubuntu 24.04 LTS must be configured so that remote X connections are disabled, unless to fulfill documented and validated mission requirements. prevents CWE-1188
Windows Server 2016 (1 rule)
  • V-224972 Active Directory Group Policy objects must have proper access control permissions. prevents CWE-1188
Windows Server 2019 (1 rule)
  • V-205741 Windows Server 2019 Active Directory Group Policy objects must have proper access control permissions. prevents CWE-1188

References