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NVD / CVE Program· CNA redhat

CVE-2026-35092: Corosync: corosync: denial of service via integer overflow in join message validation

HighCVSS 7.5 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 30/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 1% (FIRST EPSS); higher than 63.6% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: corosync (AlmaLinux:10) 3.1.10-1.el10_2.1, 3.1.9-2.el10_1.1; corosync-vqsim (AlmaLinux:10) 3.1.10-1.el10_2.1, 3.1.9-2.el10_1.1; corosynclib (AlmaLinux:10) 3.1.9-2.el10_1.1, 3.1.10-1.el10_2.1.

Low priority for now. Upgrade to corosync (AlmaLinux:10) 3.1.10-1.el10_2.1, 3.1.9-2.el10_1.1; corosync-vqsim (AlmaLinux:10) 3.1.10-1.el10_2.1, 3.1.9-2.el10_1.1; corosynclib (AlmaLinux:10) 3.1.9-2.el10_1.1, 3.1.10-1.el10_2.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A flaw was found in Corosync. An integer overflow vulnerability in Corosync's join message sanity validation allows a remote, unauthenticated attacker to send crafted User Datagram Protocol (UDP) packets. This can cause the service to crash, leading to a denial of service. This vulnerability specifically affects Corosync deployments configured to use totemudp/totemudpu mode.

Published
Apr 1, 2026
Updated
Oct 26, 2026
EPSS
1.0% · 63th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 1.0%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · redhat
7.5
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
corosynccorosync
redhatopenshift
redhatenterprise linux

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

  • Red Hat Red Hat Enterprise Linux 10

    • 0:3.1.9-2.el10_1.1 and laternot affected · rpm
    • 0:3.1.10-1.el10_2.1 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support

    • 0:3.1.9-1.el10_0.2 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support

    • 0:2.4.5-7.el7_9.3 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 8

    • 0:3.1.8-1.el8_10.1 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support

    • 0:3.1.0-3.el8_4.2 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

    • 0:3.1.0-3.el8_4.2 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support

    • 0:3.1.5-2.el8_6.1 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 8.6 Telecommunications Update Service

    • 0:3.1.5-2.el8_6.1 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions

    • 0:3.1.5-2.el8_6.1 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service

    • 0:3.1.7-1.el8_8.1 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions

    • 0:3.1.7-1.el8_8.1 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 9

    • 0:3.1.9-2.el9_7.1 and laternot affected · rpm
    • 0:3.1.10-1.el9_8.1 and laternot affected · rpm
Affected versions · NVD (6)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • corosync corosyncall versions
  • redhat enterprise linux10.0
  • redhat enterprise linux7.0
  • redhat enterprise linux8.0
  • redhat enterprise linux9.0
  • redhat openshift4.0

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10corosyncbefore 3.1.10-1.el10_2.13.1.10-1.el10_2.1
AlmaLinux:10corosyncbefore 3.1.9-2.el10_1.13.1.9-2.el10_1.1
AlmaLinux:10corosync-vqsimbefore 3.1.10-1.el10_2.13.1.10-1.el10_2.1
AlmaLinux:10corosync-vqsimbefore 3.1.9-2.el10_1.13.1.9-2.el10_1.1
AlmaLinux:10corosynclibbefore 3.1.9-2.el10_1.13.1.9-2.el10_1.1
AlmaLinux:10corosynclibbefore 3.1.10-1.el10_2.13.1.10-1.el10_2.1
AlmaLinux:10corosynclib-develbefore 3.1.9-2.el10_1.13.1.9-2.el10_1.1
AlmaLinux:10corosynclib-develbefore 3.1.10-1.el10_2.13.1.10-1.el10_2.1
AlmaLinux:8corosyncbefore 3.1.8-1.el8_10.13.1.8-1.el8_10.1
AlmaLinux:8corosync-vqsimbefore 3.1.8-1.el8_10.13.1.8-1.el8_10.1
AlmaLinux:8corosynclibbefore 3.1.8-1.el8_10.13.1.8-1.el8_10.1
AlmaLinux:8corosynclib-develbefore 3.1.8-1.el8_10.13.1.8-1.el8_10.1
AlmaLinux:8spauseddbefore 3.1.8-1.el8_10.13.1.8-1.el8_10.1
AlmaLinux:9corosyncbefore 3.1.10-1.el9_8.13.1.10-1.el9_8.1
AlmaLinux:9corosyncbefore 3.1.9-2.el9_7.13.1.9-2.el9_7.1
AlmaLinux:9corosync-vqsimbefore 3.1.10-1.el9_8.13.1.10-1.el9_8.1
AlmaLinux:9corosync-vqsimbefore 3.1.9-2.el9_7.13.1.9-2.el9_7.1
AlmaLinux:9corosynclibbefore 3.1.10-1.el9_8.13.1.10-1.el9_8.1
AlmaLinux:9corosynclibbefore 3.1.9-2.el9_7.13.1.9-2.el9_7.1
AlmaLinux:9corosynclib-develbefore 3.1.10-1.el9_8.13.1.10-1.el9_8.1
AlmaLinux:9corosynclib-develbefore 3.1.9-2.el9_7.13.1.9-2.el9_7.1
Debian:12corosyncbefore 3.1.7-1+deb12u23.1.7-1+deb12u2
Debian:13corosyncbefore 3.1.9-2+deb13u13.1.9-2+deb13u1
Debian:14corosyncbefore 3.1.10-23.1.10-2

+96

Same product

corosync: all records

Other highest-scoring records for the same primary product.

  • CVE-2025-30472Corosync through 3.1.9, if encryption is disabled or the attacker knows the encryption key, has a stack-based buffer overflow in…
    39Monitor
  • CVE-2026-35091Corosync: corosync: denial of service and information disclosure via crafted udp packet
    32Monitor
  • CVE-2018-1084corosync before version 2.4.4 is vulnerable to an integer overflow in exec/totemcrypto.c.
    31Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2013-0250Jun 6, 2014 · The init_nss_hash function in exec/totemcrypto.c in Corosync 2.0 before 2.3 does not properly initialize the HMAC key, which allows remote…
    21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
almalinux:corosync3.1.9-2.el10_1.1 · AlmaLinux:10Package registry (OSV)
almalinux:corosync-vqsim3.1.9-2.el10_1.1 · AlmaLinux:10Package registry (OSV)
almalinux:corosynclib3.1.9-2.el10_1.1 · AlmaLinux:10Package registry (OSV)
almalinux:corosynclib-devel3.1.9-2.el10_1.1 · AlmaLinux:10Package registry (OSV)
almalinux:spausedd3.1.8-1.el8_10.1 · AlmaLinux:8Package registry (OSV)
debian:corosync3.1.7-1+deb12u2 · Debian:12Package registry (OSV)
opensuse:corosync2.4.6-150300.12.16.1 · openSUSE:Leap 15.6Package registry (OSV)
red hat:corosync0:3.1.9-2.el10_1.1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:corosync-debuginfo0:3.1.9-2.el10_1.1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:corosync-debugsource0:3.1.9-2.el10_1.1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:corosync-qdevice0:2.4.5-7.el7_9.3 · Red Hat:enterprise_linux:7::serverPackage registry (OSV)
red hat:corosync-qnetd0:2.4.5-7.el7_9.3 · Red Hat:enterprise_linux:7::serverPackage registry (OSV)
red hat:corosync-vqsim0:3.1.9-2.el10_1.1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:corosync-vqsim-debuginfo0:3.1.9-2.el10_1.1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:corosynclib0:3.1.9-2.el10_1.1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:corosynclib-debuginfo0:3.1.9-2.el10_1.1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:corosynclib-devel0:3.1.9-2.el10_1.1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:spausedd0:3.1.8-1.el8_10.1 · Red Hat:enterprise_linux:8::highavailabilityPackage registry (OSV)
red hat:spausedd-debuginfo0:3.1.8-1.el8_10.1 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
rocky linux:corosync0:3.1.9-2.el10_1.1 · Rocky Linux:10Package registry (OSV)
suse:corosync2.4.6-150300.12.16.1 · SUSE:Linux Enterprise High Availability Extension 15 SP4Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Not on record for this CVE: EPSS history · patch commit or PR link · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-190 · Integer Overflow or Wraparound

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Show all references (15 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records