# CVE-2026-109140: Krill login-session tokens reuse their encryption nonce across restarts, so any user who can log in can forge an "admin" token

Status: published. Published: 2026-11-02. Updated: 2026-11-02.

The vulnerability is that Krill encrypts every login-session token with a nonce built from a counter that is reset to 0 on every Krill restart, so the same (key, nonce) pair is used again after each restart.

## Remediation

- fix: This issue is fixed in 0.16.1 and all later versions. (source: CNA: NLnet Labs)

## Affected products and versions

- NLnet Labs / Krill: ≥ 0.16.1; < * (unaffected, semver). Source: CNA: NLnet Labs

## Severity and prioritization

- CVSS 3.1: 8.4 (high); CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L; source: CNA: NLnet Labs

- CVSS 3.1: 8.4 (high); CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L; source: NVD: sep@nlnetlabs.nl

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-323

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://www.nlnetlabs.nl/downloads/krill/CVE-2026-109140.txt (CNA: NLnet Labs; vendor-advisory)

- https://www.nlnetlabs.nl/downloads/krill/CVE-2026-109140.txt (sep@nlnetlabs.nl)

## Provenance

- CNA: NLnet Labs: https://www.cve.org/CVERecord?id=CVE-2026-109140; retrieved 2026-11-02; source updated 2026-11-02

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-109140; retrieved 2026-11-02; source updated 2026-11-02

Revision: d5843afbcdd2908ce12e2caf8167e5c4268a22cbe349d968316b745ede1446af

Canonical: https://y2.dev/cve/CVE-2026-109140

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