VDB-408898 · CVE-2026-91999 · WID-SEC-2026-3526

Apache Sling cross site scripting

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
2.4	$0-$5k	0.21-

Summaryinfo

A vulnerability classified as problematic was found in Apache Sling. The affected element is an unknown function. Executing a manipulation can lead to cross site scripting. This vulnerability appears as CVE-2026-91999. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability classified as problematic was found in Apache Sling (version unknown). This vulnerability affects an unknown function. The manipulation with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. As an impact it is known to affect integrity.

This vulnerability was named CVE-2026-91999. The exploitation appears to be easy. The attack can be initiated remotely. Additional levels of successful authentication are necessary for exploitation. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 09/24/2026). This vulnerability is assigned to T1059.007 by the MITRE ATT&CK project.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-3526). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

Apache Sling

Productinfo

Vendor

Apache

Name

Sling

License

open-source

Website

Vendor: https://www.apache.org/

CPE 2.3info

🔒

CPE 2.2info

🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 2.4
VulDB Meta Temp Score: 2.4

VulDB Base Score: 2.4
VulDB Temp Score: 2.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Cross site scripting
CWE: CWE-79 / CWE-94 / CWE-74
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

09/23/2026 Advisory disclosed
09/23/2026 +0 days VulDB entry created
09/24/2026 +1 days VulDB entry last update

Sourcesinfo

Vendor: apache.org

Status: Not defined

CVE: CVE-2026-91999 (🔒)
GCVE (CVE): GCVE-0-2026-91999
GCVE (VulDB): GCVE-100-408898
CERT Bund: WID-SEC-2026-3526 - Apache Sling: Mehrere Schwachstellen

Entryinfo

Created: 09/23/2026 11:14
Updated: 09/24/2026 08:12
Changes: 09/23/2026 11:14 (46), 09/24/2026 08:12 (7)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.