CVE-2026-103655 MISP TOTP Code Replay Allows Duplicate Authentication Within Validity Period
Attackers can replay captured TOTP codes to bypass two-factor authentication and access user accounts within the validity window.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-103655?
CVE-2026-103655 is a critical authentication bypass vulnerability in MISP, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
MISP contains a vulnerability in its two-factor authentication (TOTP) verification process that permits a valid one-time code to be accepted more than once within its time-based validity window.
The issue exists in the user login flow where a TOTP code is verified as a second authentication factor. Because the system did not record whether a given TOTP period had already been consumed, the same code remained valid for its entire time window (typically 30 seconds). An attacker who captures a legitimate code during a user's login could replay it to authenticate a second session as that user.
Preconditions:
- The target user has TOTP-based two-factor authentication enabled.
- The attacker is in a position to observe or intercept the TOTP code during a legitimate login (e.g., network-level interception, shoulder surfing, or a compromised client).
- The replay must occur within the TOTP validity period.
Security impact:
- Unauthorized account access by replaying a captured one-time code.
- Potential compromise of threat-intelligence data and administrative functions accessible to the targeted user.
Affected versions: <v2.5.48.
Weakness: CWE-294
Which versions are affected by CVE-2026-103655?
How do I fix CVE-2026-103655?
No fix has been published for CVE-2026-103655 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-103655 being exploited?
There is no known exploitation of CVE-2026-103655 in the wild and no public exploit code.
Sources
Also known as GHSA-2hxj-rrwr-5g5v.