Red Hat Enterprise Linux 10: Incorrect Check of Function Return Value
CVE-2026-35091 is a high-severity incorrect check of function return value vulnerability in Red Hat Enterprise Linux 10 from Red Hat, with a CVSS 3.1 base score of 8.2 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 0.88% chance of exploitation within 30 days, higher than 60% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Red Hat Enterprise Linux 10 you run against the affected versions below, and install the vendor's latest release.
- 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
- NoneNothing can be modified.
- 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:N/A:H. Scored by CNA (redhat.com).
Official description
A flaw was found in Corosync. A remote unauthenticated attacker can exploit a wrong return value vulnerability in the Corosync membership commit token sanity check by sending a specially crafted User Datagram Protocol (UDP) packet. This can lead to an out-of-bounds read, causing a denial of service (DoS) and potentially disclosing limited memory contents
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Check of Function Return Value
The product incorrectly checks a return value from a function, which prevents it from detecting errors or exceptional conditions.
How developers prevent this class of flaw
- Use a language or compiler that uses exceptions and requires the catching of those exceptions.
- Properly check all functions which return a value.
- When designing any function make sure you return a value or throw an exception in case of an error.
More Incorrect Check of Function Return Value vulnerabilities (CWE-253)
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
Third-party and government advisories
- access.redhat.com/security/cve/CVE-2026-35091Third Party Advisory, VDB Entry
Technical write-ups (may include proof of concept)
- bugzilla.redhat.com/show_bug.cgi?id=2453169Exploit, Third Party Advisory
Other references
- access.redhat.com/errata/RHSA-2026:13644
- access.redhat.com/errata/RHSA-2026:13657
- access.redhat.com/errata/RHSA-2026:13673
- access.redhat.com/errata/RHSA-2026:14205
- access.redhat.com/errata/RHSA-2026:14210
- access.redhat.com/errata/RHSA-2026:14211
- access.redhat.com/errata/RHSA-2026:14212
- access.redhat.com/errata/RHSA-2026:14213
- access.redhat.com/errata/RHSA-2026:14214
- access.redhat.com/errata/RHSA-2026:14215
- access.redhat.com/errata/RHSA-2026:14216
- access.redhat.com/errata/RHSA-2026:19043
- access.redhat.com/errata/RHSA-2026:19200
- access.redhat.com/errata/RHSA-2026:20916
- bugzilla.redhat.com/show_bug.cgi?id=2453813Issue Tracking
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 Incorrect Check of Function Return Value vulnerabilities
- 7.5 High severity
- 7.5 High severity
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