CVE-2026-78655

What it is

Punk::Plugin::TOTP versions before 0.05 for Perl allow the second-factor attempt limit to be reset by replaying an earlier session cookie because the challenge route counts failures in the session. The POST handler on challenge_path keeps the failure count as tries inside the totp_pending record in the session, raising it on each rejected code and deleting the pending record once it reaches attempts, five by default. Punk::Session carries the session in a signed cookie unless the application declares a store, and keeps no server-side record, so an earlier value of the same session stays valid until the expiry stamped inside it. A client that saves the cookie before its failed attempts and presents it again gets the pending record back with its counter, and the limit never fires. The replayed record is accepted while its own expiry, pending_ttl seconds from the challenge and 300 by default, has not passed. Sessions declared with a store are not affected: the pending record and its counter then live server-side. The attempt limit does not bound guessing of the second factor, which is left to the per-address rate limit the plugin registers on the same path, 30 requests per 60 seconds.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2026-08-24 23:12 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-08-25 22:17 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-08-26 20:18 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.5% in the next 30 days (EPSS).
• Severity: 9.1 CRITICAL (CVSS).
• Fix: none linked yet, which raises it.

Details

Published

2026-08-25 22:17 UTC

Last modified

2026-08-26 20:18 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-307

Record status

Deferred

Attack profile CVSS 3.1 · 9.1

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-78655.md and follow it. Check whether this project is affected by CVE-2026-78655. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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