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🛡️ CVE-2026-35091 on Ubuntu — corosync

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

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

Distribution advisory

This page covers CVE-2026-35091 as tracked by Ubuntu, for the package corosync. The fix is available in version 3.1.9-2ubuntu1.1; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality low, integrity none, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: None — an unauthenticated stranger can try it.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: Low — limited, and the attacker does not choose what is affected.
  • Integrity impact: None.
  • Availability impact: High — total loss, or loss the attacker controls.

Weakness class

UBUNTU-CVE-2026-35091 is classified as CWE-253: 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.

Affected software

UBUNTU-CVE-2026-35091 is recorded against 1 package.

  • corosync (fixed in 3.1.9-2ubuntu1.1)

Timeline and source

Published on 1 April 2026 and last revised on 20 May 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

ubuntu.com (Report)
www.cve.org (Report)
ubuntu.com (Advisory)

Other advisories for this package

corosync has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-253: Incorrect Check of Function Return Value) in other software:

CVE-2026-35091 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2026-04-01
Updated 2026-08-20
Modified 2026-05-20
Fix URL N/A

Affected Packages

Software From version Fixed in
corosync — 3.1.9-2ubuntu1.1

Similar Threats

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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