CVE-2025-26465: Openssh: machine-in-the-middle attack if verifyhostkeydns is enabled
Noroxi assessment
Priority: Monitor (action score 29/100)
- Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
- Probability of exploitation in the next 30 days: 7.7% (FIRST EPSS); higher than 94.5% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. Special conditions such as timing or configuration are required.
- Fixed version: azl3 openssh 9.8p1-3 on Azure Linux 3.0 9.8p1-3; azl3 openssh 9.8p1-4 on Azure Linux 3.0 9.8p1-3; cbl2 openssh 8.9p1-7 on CBL Mariner 2.0 8.9p1-7.
Low priority for now. Upgrade to azl3 openssh 9.8p1-3 on Azure Linux 3.0 9.8p1-3; azl3 openssh 9.8p1-4 on Azure Linux 3.0 9.8p1-3; cbl2 openssh 8.9p1-7 on CBL Mariner 2.0 8.9p1-7 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 vulnerability was found in OpenSSH when the VerifyHostKeyDNS option is enabled. A machine-in-the-middle attack can be performed by a malicious machine impersonating a legit server. This issue occurs due to how OpenSSH mishandles error codes in specific conditions when verifying the host key. For an attack to be considered successful, the attacker needs to manage to exhaust the client's memory resource first, turning the attack complexity high.
- Published
- Feb 18, 2025
- Updated
- Oct 21, 2026
- EPSS
- 7.7% · 94th percentile
- CWE
- CWE-390
Report tools
Action score
29
Monitor
Low priority for now.
- CVSS
- 27 / 40 · 6.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 2 / 30 · 7.7%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 6.8
- CNA · redhat
- 6.8
- agree
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
- Proof of concept exists, no weaponized module
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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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.
We use this product, ask for helpAffected 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.
| Vendor | Product | CPE |
|---|---|---|
| openbsd | openssh | cpe:2.3:a:openbsd:openssh |
| netapp | active iq unified manager | cpe:2.3:a:netapp:active_iq_unified_manager |
| netapp | ontap | cpe:2.3:a:netapp:ontap |
| redhat | openshift container platform | cpe:2.3:a:redhat:openshift_container_platform |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
| redhat | enterprise linux | cpe:2.3:o:redhat:enterprise_linux |
Is OpenSSH on your server exposed to the internet?
The free port scanner finds the open ports on your server and matches the service versions it can read against known vulnerabilities. No account needed.
Run a port scanAffected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- debian debian linux11.0
- debian debian linux12.0
- netapp active iq unified managerall versions
- netapp ontap9
- openbsd openssh6.9 and later · up to 9.8 inclusive
- openbsd openssh6.8
- openbsd openssh9.9
- redhat enterprise linux9.0
- redhat openshift container platform4.0
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 Discovery 1.14
- 1.14.3-1748529279 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 10
- all versionsunknown
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
- 0:8.0p1-26.el8_10 and laternot affected · rpm
- 0:8.0p1-26.el8_10 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 9
- 0:8.7p1-45.el9 and laternot affected · rpm
- 0:8.7p1-45.el9 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 9.4 Extended Update Support
- 0:8.7p1-38.el9_4.5 and laternot affected · rpm
Red Hat Red Hat OpenShift Container Platform 4
- all versionsaffected
www.openssh.com/ OpenSSH
- 6.8p1 and later · up to and including 9.9p1affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | openssh | before 8.0p1-26.el8_10 | 8.0p1-26.el8_10 |
| AlmaLinux:8 | openssh-askpass | before 8.0p1-26.el8_10 | 8.0p1-26.el8_10 |
| AlmaLinux:8 | openssh-cavs | before 8.0p1-26.el8_10 | 8.0p1-26.el8_10 |
| AlmaLinux:8 | openssh-clients | before 8.0p1-26.el8_10 | 8.0p1-26.el8_10 |
| AlmaLinux:8 | openssh-keycat | before 8.0p1-26.el8_10 | 8.0p1-26.el8_10 |
| AlmaLinux:8 | openssh-ldap | before 8.0p1-26.el8_10 | 8.0p1-26.el8_10 |
| AlmaLinux:8 | openssh-server | before 8.0p1-26.el8_10 | 8.0p1-26.el8_10 |
| AlmaLinux:8 | pam_ssh_agent_auth | before 0.10.3-7.26.el8_10 | 0.10.3-7.26.el8_10 |
| AlmaLinux:9 | openssh | before 8.7p1-45.el9 | 8.7p1-45.el9 |
| AlmaLinux:9 | openssh-askpass | before 8.7p1-45.el9 | 8.7p1-45.el9 |
| AlmaLinux:9 | openssh-clients | before 8.7p1-45.el9 | 8.7p1-45.el9 |
| AlmaLinux:9 | openssh-keycat | before 8.7p1-45.el9 | 8.7p1-45.el9 |
| AlmaLinux:9 | openssh-server | before 8.7p1-45.el9 | 8.7p1-45.el9 |
| AlmaLinux:9 | pam_ssh_agent_auth | before 0.10.4-5.45.el9 | 0.10.4-5.45.el9 |
| Alpine:v3.18 | openssh | from 6.9 · before 9.3_p2-r3 | 9.3_p2-r3 |
| Alpine:v3.19 | openssh | from 6.9 · before 9.6_p1-r2 | 9.6_p1-r2 |
| Alpine:v3.20 | openssh | from 6.9 · before 9.7_p1-r5 | 9.7_p1-r5 |
| Alpine:v3.21 | openssh | from 6.9 · before 9.9_p2-r0 | 9.9_p2-r0 |
| Debian:11 | openssh | before 1:8.4p1-5+deb11u4 | 1:8.4p1-5+deb11u4 |
| Debian:12 | openssh | before 1:9.2p1-2+deb12u5 | 1:9.2p1-2+deb12u5 |
| Debian:13 | openssh | before 1:9.9p2-1 | 1:9.9p2-1 |
| openSUSE:Leap 15.6 | openssh | before 9.6p1-150600.6.15.2 | 9.6p1-150600.6.15.2 |
| openSUSE:Leap 15.6 | openssh-askpass-gnome | before 9.6p1-150600.6.15.1 | 9.6p1-150600.6.15.1 |
| openSUSE:Tumbleweed | openssh | before 9.9p2-1.1 | 9.9p2-1.1 |
+56
Same product
openbsd: all recordsOther highest-scoring records for the same primary product.
- CVE-2023-38408The PKCS#11 feature in ssh-agent in OpenSSH before 9.3p2 has an insufficiently trustworthy search path, leading to remote code execution if 63This week
- CVE-2018-15473OpenSSH through 7.7 is prone to a user enumeration vulnerability due to not delaying bailout for an invalid authenticating user until after 60This week
- CVE-2016-6210sshd in OpenSSH before 7.3, when SHA256 or SHA512 are used for user password hashing, uses BLOWFISH hashing on a static password when the us60This week
Published before and after this one in the same product
- ← EarlierCVE-2023-51385Dec 18, 2023 · In ssh in OpenSSH before 9.6, OS command injection might occur if a user name or host name has shell metacharacters, and this name is refere32Monitor
- ← EarlierCVE-2023-51767Dec 24, 2023 · OpenSSH through 10.0, when common types of DRAM are used, might allow row hammer attacks (for authentication bypass) because the integer val28Monitor
- Later →CVE-2025-26466Feb 28, 2025 · Openssh: denial-of-service in openssh35Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| azl3 openssh 9.8p1-3 on Azure Linux 3.0 | 9.8p1-3 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 openssh 9.8p1-4 on Azure Linux 3.0 | 9.8p1-3 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 openssh 8.9p1-7 on CBL Mariner 2.0 | 8.9p1-7 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 openssh 8.9p1-8 on CBL Mariner 2.0 | 8.9p1-7 · CBL-Mariner Releases | Microsoft (MSRC) |
| cbl2 openssh 8.9p1-8 on CBL-Mariner 2.0 | 8.9p1-7 · CBL-Mariner Releases | Microsoft (MSRC) |
| almalinux:openssh | 8.0p1-26.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:openssh-askpass | 8.0p1-26.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:openssh-cavs | 8.0p1-26.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:openssh-clients | 8.0p1-26.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:openssh-keycat | 8.0p1-26.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:openssh-ldap | 8.0p1-26.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:openssh-server | 8.0p1-26.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:pam_ssh_agent_auth | 0.10.3-7.26.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| alpine:openssh | 9.3_p2-r3 · Alpine:v3.18 | Package registry (OSV) |
| debian:openssh | 1:9.2p1-2+deb12u5 · Debian:12 | Package registry (OSV) |
| opensuse:openssh | 9.6p1-150600.6.15.2 · openSUSE:Leap 15.6 | Package registry (OSV) |
| opensuse:openssh-askpass-gnome | 9.6p1-150600.6.15.1 · openSUSE:Leap 15.6 | Package registry (OSV) |
| red hat:openssh | 0:8.0p1-26.el8_10 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:openssh-askpass | 0:8.0p1-26.el8_10 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:openssh-askpass-debuginfo | 0:8.0p1-26.el8_10 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:openssh-cavs | 0:8.0p1-26.el8_10 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:openssh-cavs-debuginfo | 0:8.0p1-26.el8_10 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:openssh-clients-debuginfo | 0:8.0p1-26.el8_10 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:openssh-debuginfo | 0:8.0p1-26.el8_10 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:openssh-debugsource | 0:8.0p1-26.el8_10 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:openssh-keycat-debuginfo | 0:8.0p1-26.el8_10 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:openssh-ldap-debuginfo | 0:8.0p1-26.el8_10 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:openssh-server-debuginfo | 0:8.0p1-26.el8_10 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:pam_ssh_agent_auth-debuginfo | 0:0.10.3-7.26.el8_10 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| rocky linux:openssh | 0:8.0p1-26.el8_10 · Rocky Linux:8 | Package registry (OSV) |
+3
Exploit status
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Proof-of-concept repository on GitHub ×2
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Proof-of-concept repository on GitHub | stars:9 | 2025-02-18 |
| Proof-of-concept repository on GitHub | stars:1 | 2025-02-21 |
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.
- First PoC-1 d
- Published
- TodayOct 27, 2026+615 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
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 researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
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
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- None
Weakness class (CWE)
CWE-390 · Detection of Error Condition Without ActionCVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
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.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (19 more)Show less
- access.redhat.com/errata/RHSA-2025:3837
- access.redhat.com/errata/RHSA-2025:6993
- access.redhat.com/errata/RHSA-2025:8385
- access.redhat.com/security/cve/CVE-2025-26465
- access.redhat.com/solutions/7109879
- bugzilla.redhat.com/show_bug.cgi?id=2344780
- seclists.org/oss-sec/2025/q1/144
- seclists.org/fulldisclosure/2025/Feb/18
- seclists.org/fulldisclosure/2025/May/7
- seclists.org/fulldisclosure/2025/May/8
- blog.qualys.com/vulnerabilities-threat-research/2025/02/18/qualys-tru-discovers-two-vulnerabilities-in-openssh-cve-2025-26465-cve-2025-26466
- bugzilla.suse.com/show_bug.cgi?id=1237040
- ftp.openbsd.org/pub/OpenBSD/patches/7.6/common/008_ssh.patch.sig
- lists.debian.org/debian-lts-announce/2025/02/msg00020.html
- lists.mindrot.org/pipermail/openssh-unix-announce/2025-February/000161.html
- security-tracker.debian.org/tracker/CVE-2025-26465
- security.netapp.com/advisory/ntap-20250228-0003/
- ubuntu.com/security/CVE-2025-26465
- www.openssh.com/releasenotes.html#9.9p2
Vendor advisories and official records. Exploit/PoC links are deliberately left out.