F5 NGINX Open Source up to 1.30.0 encoding error

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.4$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic has been found in F5 NGINX Open Source up to 1.30.0. Affected is an unknown function. The manipulation leads to encoding error. This vulnerability is listed as CVE-2026-42926. The attack may be initiated remotely. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in F5 NGINX Open Source up to 1.30.0. This issue affects some unknown processing. The manipulation with an unknown input leads to a encoding error vulnerability. Using CWE to declare the problem leads to CWE-172. The product does not properly encode or decode the data, resulting in unexpected values. Impacted is integrity. The summary by CVE is:

When NGINX Open Source is configured to proxy HTTP/2 traffic by setting proxy_http_version to 2, and also uses proxy_set_body, an attacker may be able to inject frame headers and payload bytes to the upstream peer.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

The advisory is shared at my.f5.com. The identification of this vulnerability is CVE-2026-42926 since 05/05/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 06/30/2026).

The vulnerability scanner Nessus provides a plugin with the ID 314992 (Fedora 42 : nginx / nginx-mod-brotli / nginx-mod-fancyindex / etc (2026-38623b4fed)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.30.1 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (314992) and CERT Bund (WID-SEC-2026-1527). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Fedora Linux
  • Ubuntu Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • NGINX NGINX Plus
  • NGINX NGINX
  • SUSE Linux

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.5
VulDB Meta Temp Score: 5.4

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.8
CNA Vector: 🔒

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Encoding error
CWE: CWE-172
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 314992
Nessus Name: Fedora 42 : nginx / nginx-mod-brotli / nginx-mod-fancyindex / etc (2026-38623b4fed)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: NGINX Open Source 1.30.1

Timelineinfo

05/05/2026 CVE reserved
05/13/2026 +8 days Advisory disclosed
05/13/2026 +0 days VulDB entry created
06/30/2026 +48 days VulDB entry last update

Sourcesinfo

Vendor: f5.com

Advisory: K000161131
Status: Confirmed

CVE: CVE-2026-42926 (🔒)
GCVE (CVE): GCVE-0-2026-42926
GCVE (VulDB): GCVE-100-363593
CERT Bund: WID-SEC-2026-1527 - NGINX Open Source and NGINX Plus: Mehrere Schwachstellen

Entryinfo

Created: 05/13/2026 17:50
Updated: 06/30/2026 16:02
Changes: 05/13/2026 17:50 (75), 05/15/2026 21:18 (7), 05/16/2026 10:02 (2), 06/30/2026 16:02 (1)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

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