Red Hat Enterprise Linux 10: Out-of-bounds Read
CVE-2026-102559 is a high-severity out-of-bounds read vulnerability in Red Hat Enterprise Linux 10 from Red Hat, with a CVSS 3.1 base score of 8.6 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.63% chance of exploitation within 30 days, higher than 51% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Libsoup to 3.7.3 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- LowSome restricted data can be read.
- Integrity
- LowLimited modification of data is possible.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.6 | High | CNA (redhat.com) |
| CVSS 3.1 | 8.6 | High | NVD |
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- access.redhat.com/security/cve/CVE-2026-102559Mitigation, Third Party Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2543285Issue Tracking, Third Party Advisory
Third-party and government advisories
- access.redhat.com/errata/RHSA-2026:83384Third Party Advisory
- access.redhat.com/errata/RHSA-2026:83618Third Party Advisory
Other references
- access.redhat.com/errata/RHSA-2026:84586
- access.redhat.com/errata/RHSA-2026:92347
- access.redhat.com/errata/RHSA-2026:93445
- access.redhat.com/errata/RHSA-2026:93446
- access.redhat.com/errata/RHSA-2026:93447
- access.redhat.com/errata/RHSA-2026:93465
- access.redhat.com/errata/RHSA-2026:93466
- access.redhat.com/errata/RHSA-2026:93583
- access.redhat.com/errata/RHSA-2026:93716
- access.redhat.com/errata/RHSA-2026:98453
- access.redhat.com/errata/RHSA-2026:98560
Other vulnerabilities in Red Hat Enterprise Linux 10
- 8.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.9 High severity
- 7.3 High severity
- 7.5 High severity
Recent Out-of-bounds Read vulnerabilities
- 8.5 High severity
- 7.1 High severity
- 7.1 High severity
- 8.7 High severity
- 7.1 High severity
- 8.3 High severity
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