# CVE-2026-107168: M17n-lib: parser infinite loop on malformed utf-8 in count_utf_8_chars()

Status: published. Published: 2026-10-07. Updated: 2026-11-05.

A flaw was found in m17n-lib. By providing crafted input containing an invalid UTF-8 character sequence, an attacker can cause the text parsing function to enter an infinite loop. This issue leads to sustained high CPU utilization, resulting in a Denial of Service (DoS) for the affected application.

## Remediation

- workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Enterprise Linux 10 (m17n-lib): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 6 (m17n-lib): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (m17n-lib): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (m17n-lib): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (m17n-lib): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 6.2 (medium); CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H; source: CNA: redhat

- CVSS 3.1: 6.2 (medium); CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H; source: NVD: secalert@redhat.com

- CISA KEV: No listing in collected sources

- EPSS: 0.11% as of 2026-11-05; percentile 1.40%

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

- Weaknesses: CWE-835

## Exploit evidence

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

## References

- https://access.redhat.com/security/cve/CVE-2026-107168 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2547409 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-107168 (secalert@redhat.com)

- https://bugzilla.redhat.com/show_bug.cgi?id=2547409 (secalert@redhat.com)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-107168; retrieved 2026-11-05; source updated 2026-11-05

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-107168; retrieved 2026-11-05; source updated 2026-11-05

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-107168; retrieved 2026-11-05; source updated Not reported

Revision: f3ce3eb7cb542b13fe60968a773d3f846ab3394e5670c42d23b009d28c2b074e

Canonical: https://y2.dev/cve/CVE-2026-107168

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