Runtipi has a TOTP two-factor authentication bypass via unrestricted brute-force on `/api/auth/verify-totp`

published 2026-03-13 7 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-12180

cvss: 8.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 33%
public exploits: 0; none known

Runtipi is a personal homeserver orchestrator. Prior to 4.8.1, The Runtipi /api/auth/verify-totp endpoint does not enforce any rate limiting, attempt counting, or account lockout mechanism. An attacker who has obtained a user's valid credentials (via phishing, credential stuffing, or data breach) can brute-force the 6-digit TOTP code to completely bypass two-factor authentication. The TOTP verification session persists for 24 hours (default cache TTL), providing an excessive window during which the full 1,000,000-code keyspace (000000–999999) can be exhausted. At practical request rates (~500 req/s), the attack completes in approximately 33 minutes in the worst case. This vulnerability is fixed in 4.8.1.

Patch / fix

fixed in 1

runtipi runtipi 4.8.1

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: total
Assessed: 7 mo ago (2026-03-16)

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 33% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/runtipi/runtipi/security/advisories/GHSA-v6gf-frxm-567w referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.1	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
NVD	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

runtipi runtipi

Classification

Weakness

CWE-307 Improper Restriction of Excessive Authentication Attempts
CWE-799 Improper Control of Interaction Frequency

References

github.com /runtipi/runtipi/security/advisories/GHSA-v6gf-frxm-567w
exploit, mitigation, vendor-advisory

Sources

CVE List CVE-2026-32729
NVD CVE-2026-32729

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary