---
cve: "CVE-2026-101019"
severity: "HIGH"
cvss: 8.3
epss: "0.2%"
vendor: "F5"
kev: false
exploited: false
published: "2026-10-14 15:17:01"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-11-10T14:28:45+01:00"
---

# CVE-2026-101019

> 8.3 HIGH

## Beschreibung

Description
NGINX JavaScript (njs) has a vulnerability where the njs XML module exposes entity-backed XML attributes inconsistently with libxml2 canonicalization. In both the built-in njs and QuickJS backends during the canonicalization process, the $attr$Name getter may return undefined for an explicitly present attribute containing an internal entity reference. The $attrs getter may return a value derived only from the first attribute child. This may allow an unauthenticated attacker that invests significant effort in obtaining a genuinely signed document to skip validation while signature verification succeeds. An nginx-saml deployment is a confirmed affected consumer when run with the built-in njs backend.

Impact
In affected signed-XML consumers, an unauthenticated attacker can cause security-relevant attributes to appear absent or truncated while signature verification succeeds. In nginx-saml, this can bypass expiry, Destination, and request-correlation checks, enabling replay or acceptance of a response outside its intended context. It does not permit signature or identity forgery, or a direct availability impact. There is no control plane exposure; this is a data plane issue only.



 Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

## CNA-Record (Kanon, cvelistV5)

- CNA: **f5**
- State: PUBLISHED
- Stand: 2026-10-15 16:43:46
- CNA-CVSS: **6.5** (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **no**
  - Technical Impact: **partial**

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Schwachstellen-Klasse

- **CWE-436** — Interpretation Conflict
  Product A handles inputs or steps differently than Product B, which causes A to perform incorrect actions based on its perception of B's state.

## Angriffsmuster (CAPEC)

- [CAPEC-34 — HTTP Response Splitting](https://capec.mitre.org/data/definitions/34.html) _(Severity: High)_
- [CAPEC-105 — HTTP Request Splitting](https://capec.mitre.org/data/definitions/105.html) _(Severity: High)_
- [CAPEC-273 — HTTP Response Smuggling](https://capec.mitre.org/data/definitions/273.html) _(Severity: High)_

## BSI-Hinweise (deutsch)

- [NGINX: Mehrere Schwachstellen](https://wid.cert-bund.de/portal/wid/sicherheitshinweis/WID-SEC-W-2026-3948) — _BSI-Einstufung: hoch_
  Ein Angreifer kann mehrere Schwachstellen in NGINX NGINX Plus und NGINX ausnutzen, um beliebigen Programmcode auszuführen, Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren und offenzulegen oder einen Denial-of-Service-Zustand auszulösen.

## Referenzen

- <https://my.f5.com/manage/s/article/K000162615>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-101019/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_