---
cve: "CVE-2026-27171"
severity: "LOW"
cvss: 2.9
epss: "22%"
vendor: "zlib"
kev: false
exploited: false
published: "2026-02-18 04:16:01"
tags: [cve, security, low]
source: tsecurity.de CVE-Dossier
exported: "2026-09-08T15:36:29+02:00"
---

# CVE-2026-27171

> 2.9 LOW · 🧪 PoC

## Beschreibung

zlib before 1.3.2 allows CPU consumption via crc32_combine64 and crc32_combine_gen64 because x2nmodp can do right shifts within a loop that has no termination condition.

## CVSS-Vektor

```
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| AC Komplexität | Hoch | good |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Keine | good |
| I Integrität | Keine | good |
| A Verfügbarkeit | Gering | warn |

## Patch verfügbar (OSV)

- da607da739fa6047df13e66a2af6b8bec7c2a498 (Commit)

## Referenzen

- <https://github.com/madler/zlib/issues/904>
- <https://7asecurity.com/reports/pentest-report-zlib-RC1.1.pdf>
- <https://7asecurity.com/blog/2026/02/zlib-7asecurity-audit/>
- <https://ostif.org/zlib-audit-complete/>
- <https://github.com/madler/zlib/releases/tag/v1.3.2>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-27171) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_