Red Hat Enterprise Linux permessage-deflate WebSocket extension heap-based overflow

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.3$5k-$25k0.56-

Summaryinfo

A vulnerability has been found in Red Hat Enterprise Linux and classified as very critical. This impacts an unknown function of the component permessage-deflate WebSocket extension. Performing a manipulation results in heap-based overflow. This vulnerability is cataloged as CVE-2026-102560. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Red Hat Enterprise Linux (the affected version unknown). This affects an unknown part of the component permessage-deflate WebSocket extension. The manipulation with an unknown input leads to a heap-based overflow vulnerability. CWE is classifying the issue as CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

A flaw was found in libsoup. When the permessage-deflate WebSocket extension compresses a very large outgoing message, truncated size calculations used for GByteArray growth could wrap, causing zlib to write past the allocated buffer and resulting in a heap buffer overflow.

It is possible to read the advisory at access.redhat.com. This vulnerability is uniquely identified as CVE-2026-102560 since 09/29/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/29/2026).

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

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.3
VulDB Meta Temp Score: 9.3

VulDB Base Score: 10.0
VulDB Temp Score: 10.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.6
CNA Vector (redhat): 🔒

CVSSv2info

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

Exploitinginfo

Class: Heap-based overflow
CWE: CWE-122 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

09/29/2026 Advisory disclosed
09/29/2026 +0 days CVE reserved
09/29/2026 +0 days VulDB entry created
09/29/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: redhat.com

Advisory: access.redhat.com
Status: Not defined

CVE: CVE-2026-102560 (🔒)
GCVE (CVE): GCVE-0-2026-102560
GCVE (VulDB): GCVE-100-411519

Entryinfo

Created: 09/29/2026 19:40
Changes: 09/29/2026 19:40 (61)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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