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NVD / CVE Program· CNA redhat

CVE-2026-0967: Libssh: libssh: denial of service via inefficient regular expression processing

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.23% (FIRST EPSS).
  • Someone with local access to the system can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • Fixed version: azl3 libssh 0.10.6-5 on Azure Linux 3.0 0.10.6-6; azl3 libssh 0.10.6-6 on Azure Linux 3.0 0.10.6-7; azl3 libssh 0.10.6-7 on Azure Linux 3.0 0.10.6-7.
  • Severity is disputed: the assigning authority (CNA) scores it 2.2, NVD 5.5.

Low priority for now. Upgrade to azl3 libssh 0.10.6-5 on Azure Linux 3.0 0.10.6-6; azl3 libssh 0.10.6-6 on Azure Linux 3.0 0.10.6-7; azl3 libssh 0.10.6-7 on Azure Linux 3.0 0.10.6-7 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 libssh. A remote attacker, by controlling client configuration files or known_hosts files, could craft specific hostnames that when processed by the `match_pattern()` function can lead to inefficient regular expression backtracking. This can cause timeouts and resource exhaustion, resulting in a Denial of Service (DoS) for the client.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Mar 26, 2026
Updated
Nov 6, 2026
EPSS
0.2% · 14th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
5.5
CNA · redhat
2.2
3.3 point gap

CVSS:3.0/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L

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

Get told when this record changes

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

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-0967

When you'll hear from us

  • when it enters CISA KEV
  • 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
libsshlibssh
redhatenterprise linux

Affected versions

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

  • libssh libsshup to 0.11.3 inclusive
  • redhat enterprise linux10.0
  • redhat enterprise linux9.0

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

    • 0:0.12.0-2.el10 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 6

    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 7

    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 8

    • all versionsaffected

  • Red Hat Red Hat Enterprise Linux 9

    • 0:0.10.4-18.el9 and laternot affected · rpm
    • 0:0.10.4-18.el9 and laternot affected · rpm

  • Red Hat Red Hat Hardened Images

    • all versionsunknown

  • Red Hat Red Hat OpenShift Container Platform 4

    • all versionsaffected
    • all versionsaffected

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:10libsshbefore 0.12.0-2.el100.12.0-2.el10
AlmaLinux:10libssh-configbefore 0.12.0-2.el100.12.0-2.el10
AlmaLinux:10libssh-develbefore 0.12.0-2.el100.12.0-2.el10
AlmaLinux:9libsshbefore 0.10.4-18.el90.10.4-18.el9
AlmaLinux:9libssh-configbefore 0.10.4-18.el90.10.4-18.el9
AlmaLinux:9libssh-develbefore 0.10.4-18.el90.10.4-18.el9
Alpine:v3.23libsshbefore 0.11.4-r00.11.4-r0
Alpine:v3.24libsshbefore 0.12.0-r00.12.0-r0
Debian:12libsshbefore 0.10.6-0+deb12u30.10.6-0+deb12u3
Debian:13libsshbefore 0.11.5-0+deb13u10.11.5-0+deb13u1
Debian:14libsshbefore 0.12.0-10.12.0-1
openSUSE:Leap 15.6libsshbefore 0.9.8-150600.11.9.10.9.8-150600.11.9.1
openSUSE:Tumbleweedlibsshbefore 0.11.4-1.10.11.4-1.1
Red Hat:enterprise_linux:10.2libsshbefore 0:0.12.0-2.el100:0.12.0-2.el10
Red Hat:enterprise_linux:10.2libssh-configbefore 0:0.12.0-2.el100:0.12.0-2.el10
Red Hat:enterprise_linux:10.2libssh-debuginfobefore 0:0.12.0-2.el100:0.12.0-2.el10
Red Hat:enterprise_linux:10.2libssh-debugsourcebefore 0:0.12.0-2.el100:0.12.0-2.el10
Red Hat:enterprise_linux:10.2libssh-develbefore 0:0.12.0-2.el100:0.12.0-2.el10
Red Hat:enterprise_linux:9::appstreamlibssh-debuginfobefore 0:0.10.4-18.el90:0.10.4-18.el9
Red Hat:enterprise_linux:9::appstreamlibssh-debugsourcebefore 0:0.10.4-18.el90:0.10.4-18.el9
Red Hat:enterprise_linux:9::appstreamlibssh-develbefore 0:0.10.4-18.el90:0.10.4-18.el9
Red Hat:enterprise_linux:9::baseoslibsshbefore 0:0.10.4-18.el90:0.10.4-18.el9
Red Hat:enterprise_linux:9::baseoslibssh-configbefore 0:0.10.4-18.el90:0.10.4-18.el9
Rocky Linux:10libsshbefore 0:0.12.0-2.el100:0.12.0-2.el10

+8

Same product

libssh: all records

Other highest-scoring records for the same primary product.

  • CVE-2018-10933A vulnerability was found in libssh's server-side state machine before versions 0.7.6 and 0.8.4.
    64This week
  • CVE-2019-14889A flaw was found with the libssh API function ssh_scp_new() in versions before 0.9.3 and before 0.8.8.
    36Monitor
  • CVE-2026-59851Libssh: libssh: authentication bypass via missing gssapi principal check
    35Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-0965Mar 26, 2026 · Libssh: libssh: denial of service via improper configuration file handling
    13Monitor
  • ← EarlierCVE-2026-0966Mar 26, 2026 · Libssh: libssh: denial of service via zero-length input in ssh_get_hexa()
    32Monitor
  • Later →CVE-2026-0968Mar 26, 2026 · Libssh: libssh: denial of service due to malformed sftp message
    12Monitor

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
azl3 libssh 0.10.6-5 on Azure Linux 3.00.10.6-6 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 libssh 0.10.6-6 on Azure Linux 3.00.10.6-7 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 libssh 0.10.6-7 on Azure Linux 3.00.10.6-7 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 libssh 0.10.6-5 on CBL Mariner 2.00.10.6-6 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 libssh 0.10.6-5 on CBL-Mariner 2.00.10.6-6 · Release NotesMicrosoft (MSRC)
almalinux:libssh0.12.0-2.el10 · AlmaLinux:10Package registry (OSV)
almalinux:libssh-config0.12.0-2.el10 · AlmaLinux:10Package registry (OSV)
almalinux:libssh-devel0.12.0-2.el10 · AlmaLinux:10Package registry (OSV)
alpine:libssh0.11.4-r0 · Alpine:v3.23Package registry (OSV)
debian:libssh0.10.6-0+deb12u3 · Debian:12Package registry (OSV)
debian:libssh0.11.5-0+deb13u1 · Debian:13Package registry (OSV)
opensuse:libssh0.9.8-150600.11.9.1 · openSUSE:Leap 15.6Package registry (OSV)
red hat:libssh0:0.12.0-2.el10 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:libssh-config0:0.12.0-2.el10 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:libssh-debuginfo0:0.12.0-2.el10 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:libssh-debugsource0:0.12.0-2.el10 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:libssh-devel0:0.12.0-2.el10 · Red Hat:enterprise_linux:10.2Package registry (OSV)
rocky linux:libssh0:0.12.0-2.el10 · Rocky Linux:10Package registry (OSV)
suse:libssh0.9.8-150200.13.15.1 · SUSE:Linux Enterprise Micro 5.2Package registry (OSV)
suse:libssh0.9.8-150600.11.9.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package 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.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

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

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

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

Weakness class (CWE)

CWE-1333 · Inefficient Regular Expression Complexity

CVSS vector

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

nvd-primary

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

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (4 more)

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

All records