Cyber Resilience

CVE-2025-65203

Auth Bypass in Keepassxc-Browser ≤ 1.9.9.2

Auth BypassCSRF
Published
17 December 2025
Modified
05 January 2026
Patch / advisory
View advisory
CVSS Score v3.1 7.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N
EPSS Score 0.0012 2th percentile
Risk Priority 51 floored blend · peak EPSS

Summary

CVE-2025-65203 is a high-severity CSRF (CWE-352) vulnerability in Keepassxc Keepassxc-Browser. Its CVSS base score is 7.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Component Firmware (T1542.002); ranked at the 2th 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 IA-12 (Identity Proofing) and IA-5 (Authenticator Management) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access ControlA07:2025 Authentication FailuresA08:2025 Software or Data Integrity Failures

EU & UK References

Vulnerability Data

KeePassXC-Browser thru 1.9.9.2 autofills or prompts to fill stored credentials into documents rendered under a browser-enforced CSP directive and iframe attribute sandbox, allowing attacker-controlled script in the sandboxed document to access populated form fields and exfiltrate credentials.

CWE(s)
CWE-352CWE-353CWE-640

Related Threats

MITRE ATT&CK Enterprise Techniques

T1542.002 Component Firmware Stealth
Adversaries may modify component firmware to persist on systems.
attack.mitre.org →
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.
attack.mitre.org →
T1565 Data Manipulation Impact
Adversaries may insert, delete, or manipulate data in order to influence external outcomes or hide activity, thus threatening the integrity of the data.
attack.mitre.org →
T1565.002 Transmitted Data Manipulation Impact
Adversaries may alter data en route to storage or other systems in order to manipulate external outcomes or hide activity, thus threatening the integrity of the data.
attack.mitre.org →
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.
attack.mitre.org →
T1110 Brute Force Credential Access
Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2020-37158Shared CWE-352, CWE-640
CVE-2026-46894Shared CWE-352, CWE-640
CVE-2026-17583Shared CWE-353
CVE-2025-48811Shared CWE-353
CVE-2025-10010Shared CWE-353
CVE-2026-3856Shared CWE-353
CVE-2026-48995Shared CWE-353
CVE-2025-48500Shared CWE-353
CVE-2023-29290Shared CWE-353
CVE-2025-32882Shared CWE-353

Affected Assets

keepassxc
keepassxc-browser
≤ 1.9.9.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V3.3.2
  • V3.5.1
  • V10.2.1
  • V12.1.1

Mitigating Controls (NIST 800-53 r5) AI

SC-8 Transmission Confidentiality and Integrity good match

SC-8 directly requires mechanisms to protect integrity of transmitted data, which structurally eliminates the missing checksum weakness in protocols.

IA-12 Identity Proofing good match

Identity proofing at appropriate assurance levels ensures forgotten-password recovery cannot succeed without strong verification of the user.

IA-5 Authenticator Management good match

Authenticator management requires secure distribution, reset, and verification procedures that directly address weak password recovery flows.

AC-3 Access Enforcement partial match

Access enforcement requires verifying that state-changing requests originate from the authenticated user rather than a forged cross-site source.

SC-23 Session Authenticity partial match

Protecting session authenticity prevents attackers from replaying or forging authenticated requests via the victim's browser.

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.DS-02 full match
prevents

Directly requires integrity protection for data-in-transit via checksums or equivalent mechanisms.

PR.AA-01 mostly match
prevents

Credential lifecycle management directly includes password reset/recovery flows.

PR.AA-02 mostly match
prevents

Identity proofing is the core control that prevents weak or bypassed recovery mechanisms.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require anti-CSRF controls such as tokens or SameSite attributes.

PR.AA-03 partial match
prevents

Authentication policy covers strength/MFA but does not address recovery path weaknesses.

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.

A.8.24 Use of cryptography mostly match
prevents

Cryptographic controls can provide integrity verification for transmitted data.

A.5.17 Authentication information partial match
degrades

Strong authentication-information lifecycle rules directly address weak password-recovery flows.

A.8.20 Networks security partial match
mitigates

Network security controls can mandate integrity mechanisms on transmission protocols.

A.8.21 Security of network services partial match
prevents

Security requirements for network services can require integrity checks on data in transit.

A.8.23 Web filtering partial match
mitigates

By denying access to phishing or malicious sites, the control lowers the likelihood that a user will be tricked into submitting a forged request that performs an unintended action on another site.

A.8.25 Secure development life cycle partial match
prevents

Secure-SDLC practices can embed strong recovery design, yet the control is broader than this single weakness.

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 (3 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-353
  • V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-353
  • V-248823 OL 8 must not have the telnet-server package installed. prevents CWE-353
RHEL 8 (1 rule)
  • V-230487 RHEL 8 must not have the telnet-server package installed. prevents CWE-353

References