CVE-2026-102559
Libsoup: libsoup: heap buffer overflow during websocket client-frame masking
Description
A flaw was found in libsoup. When constructing a masked WebSocket client frame for a very large outgoing payload, size values passed to GByteArray allocation APIs could be truncated while the masking routine still used the full length, causing a heap buffer overflow.
INFO
Published Date :
Sept. 29, 2026, 6:17 p.m.
Last Modified :
Oct. 19, 2026, 5:17 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-102559
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 53f830b8-0a3f-465b-8143-3b8a9948e749 | ||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update libsoup to the latest version.
- Apply security patches for libsoup.
- Recompile affected components using updated libraries.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-102559.
| URL | Resource |
|---|---|
| https://access.redhat.com/errata/RHSA-2026:83384 | Third Party Advisory |
| https://access.redhat.com/errata/RHSA-2026:83618 | Third Party Advisory |
| https://access.redhat.com/errata/RHSA-2026:84586 | |
| https://access.redhat.com/security/cve/CVE-2026-102559 | Mitigation Third Party Advisory |
| https://bugzilla.redhat.com/show_bug.cgi?id=2543285 | Issue Tracking Patch Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-102559 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-102559
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-102559 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-102559 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
Oct. 19, 2026
Action Type Old Value New Value Added Affected Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/102xxx/CVE-2026-102559.json">CVE-2026-102559</a> Added Reference https://access.redhat.com/errata/RHSA-2026:84586 -
Initial Analysis by [email protected]
Oct. 16, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H Added CPE Configuration OR *cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:* *cpe:2.3:a:gnome:libsoup:*:*:*:*:*:*:*:* versions up to (excluding) 3.7.3 Added Reference Type Red Hat, Inc.: https://access.redhat.com/errata/RHSA-2026:83384 Types: Third Party Advisory Added Reference Type Red Hat, Inc.: https://access.redhat.com/errata/RHSA-2026:83618 Types: Third Party Advisory Added Reference Type Red Hat, Inc.: https://access.redhat.com/security/cve/CVE-2026-102559 Types: Mitigation, Third Party Advisory Added Reference Type Red Hat, Inc.: https://bugzilla.redhat.com/show_bug.cgi?id=2543285 Types: Issue Tracking, Patch, Third Party Advisory -
CVE Modified by [email protected]
Oct. 15, 2026
Action Type Old Value New Value Added Affected Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/102xxx/CVE-2026-102559.json">CVE-2026-102559</a> Added Reference https://access.redhat.com/errata/RHSA-2026:83618 -
CVE Modified by [email protected]
Oct. 15, 2026
Action Type Old Value New Value Added Affected Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/102xxx/CVE-2026-102559.json">CVE-2026-102559</a> Added Reference https://access.redhat.com/errata/RHSA-2026:83384 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 30, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-102559', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-30T19:42:40.159345Z'} -
New CVE Received by [email protected]
Sep. 29, 2026
Action Type Old Value New Value Added Description A flaw was found in libsoup. When constructing a masked WebSocket client frame for a very large outgoing payload, size values passed to GByteArray allocation APIs could be truncated while the masking routine still used the full length, causing a heap buffer overflow. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H Added CWE CWE-125 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/102xxx/CVE-2026-102559.json">CVE-2026-102559</a> Added Reference https://access.redhat.com/security/cve/CVE-2026-102559 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2543285