CVE-2026-14612
Description
Two off-by-one errors in the FreeIPA ipa-otpd daemon's OAuth2 device authorization handler can cause out-of-bounds memory access when processing an oversized response from a configured external OAuth2/OIDC Identity Provider. An attacker who controls or can man-in-the-middle the IdP endpoint may be able to trigger ipa-otpd to write or read one byte past the end of a fixed-size buffer. Exploitation requires FreeIPA to be configured with an external IdP, attacker control or MITM of that IdP, and a user to initiate the OAuth2 device authorization flow. The most likely impact is limited denial of service affecting the ipa-otpd daemon.
Statement
Red Hat rates this issue as Low impact. Although the flaw is reachable over the network once an external IdP is configured, exploitation is not straightforward: a successful attack would require an attacker to control, or be able to man-in-the-middle, the configured IdP endpoint and to supply an oversized device authorization response while a domain user is starting that OAuth2 login flow. We have not identified a path to arbitrary code execution, privilege escalation, or disclosure of Kerberos keys or other IdM secrets. The practical outcome is limited to instability or crash of the ipa-otpd service handling that authentication attempt.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.2 | N/A | 4.2 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:L
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:L
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
Acknowledgements
Red Hat would like to thank Andrew Rukin (Arenadata) for reporting this issue.
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