The PKCS#11 feature in ssh-agent in OpenSSH before 9.3p2 has an insufficiently trustworthy search path, leading to remote code execution if an agent is forwarded to an attacker-controlled system. (Code in /usr/lib is not necessarily safe for loading into ssh-agent.) NOTE: this issue exists because of an incomplete fix for CVE-2016-10009.
CVE-2023-38408
“—” beside the score: it is equal to NVD's CVSS score.
Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2023-07-20. NVD baseline CVSS 9.8; sources differ by 0.0.
- 8,404 internet-facing services (distinct ip:port) on record running an affected version — derived from Shodan data (© Shodan); a patched service can stay counted while its port stays open
- High exploitation likelihood — EPSS 80%
- Public exploit or proof-of-concept code is available
A fix is available — apply it.
8,404 internet-facing services (distinct ip:port) on record running a version that maps to CVE-2023-38408, in our KEV-Exposure radar’s Shodan-derived sample.
How it counts: every 12 hours, when Shodan query credits allow, the radar runs one Shodan query per tracked product, reads up to 100 ip:port services per query, and keeps a service when its banner version matches a CISA-KEV or high-EPSS CVE; a service is dropped when neither a search nor a Shodan InternetDB port re-check has refreshed it for 21 days. A re-check that finds the port still listed by Shodan InternetDB refreshes the service without re-reading the banner, so a patched service can stay counted while its port stays open. A count is a banner-version inference over a sample, not an exploit test and not an internet-wide census, and the unit is a service, not a machine: a machine answering on two ports counts twice.
- CVSS v3
- 9.8
- EG Score
- 9.8CRITICALmedium confidence
- EG Risk
- 91EG Risk 91/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity98% × 45%Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation80% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability100% × 15%CISA's SSVC Automatable value: yes (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- 80%
- EPSS %ILE
- 99th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.
- EG Severity
- 9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 80% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-22). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)3 days if the affected system is publicly exposed; 60 days if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
July 20, 2023
Last Modified
October 15, 2026
Advisory Details (10)
Auto-updated Oct 23, 2026[SECURITY] [DLA 3532-1] openssh security update
https://lists.debian.org/debian-lts-announce/2023/08/msg00021.htmlcommit f8f5a6b00398 (openbsd/src)
Fix landed in openbsd/src commit f8f5a6b00398 — awaiting tagged release
https://github.com/openbsd/src/commit/f8f5a6b003981bb824329dc987d101977beda7cacommit f03a4faa55c4 (openbsd/src)
Fix landed in openbsd/src commit f03a4faa55c4 — awaiting tagged release
https://github.com/openbsd/src/commit/f03a4faa55c4ce0818324701dadbf91988d7351dcommit 7bc29a9d5cd6 (openbsd/src)
Fix landed in openbsd/src commit 7bc29a9d5cd6 — awaiting tagged release
https://github.com/openbsd/src/commit/7bc29a9d5cd697290aa056e94ecee6253d3425f8CVE-2023-38408 OpenSSH Exploit & Vulnerability Details | Qualys
https://blog.qualys.com/vulnerabilities-threat-research/2023/07/19/cve-2023-38408-remote-code-execution-in-opensshs-forwarded-ssh-agentoss-security - Re: illumos (or at least danmcd) membership in the distros list
http://www.openwall.com/lists/oss-security/2023/09/22/9oss-security - Re: illumos (or at least danmcd) membership in the distros list
http://www.openwall.com/lists/oss-security/2023/09/22/11oss-security - Re: Announce: OpenSSH 9.3p2 released
http://www.openwall.com/lists/oss-security/2023/07/20/2oss-security - Re: CVE-2023-38408: Remote Code Execution in OpenSSH's forwarded ssh-agent
http://www.openwall.com/lists/oss-security/2023/07/20/1Vendor Advisories for CVE-2023-38408(2)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- CVE-2023-38408Microsoft Security Response Center (MSRC)Critical
The PKCS#11 feature in ssh-agent in OpenSSH before 9.3p2 has an insufficiently trustworthy search path leading to remote code execution if an agent is forwarded to an attacker-controlled system. (Code in /usr/lib is not necessarily safe for loading into ssh-agent.) NOTE: this issue exists because of an incomplete fix for CVE-2016-10009.
- GHSA-px36-p9hv-7h2vGitHub Security AdvisoriesCritical
The PKCS#11 feature in ssh-agent in OpenSSH before 9.3p2 has an insufficiently trustworthy search...
Patch Availability(12)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| ubuntu | openssh-sftp-server (1:9.0p1-1ubuntu8.4) @ lunar | 2026-10-21 | ubuntu |
| ubuntu | openssh-sftp-server (1:7.2p2-4ubuntu2.10+esm3) @ xenial | 2026-10-21 | ubuntu |
| redhat | devworkspace/devworkspace-rhel8-operator:0.22-2 | 2023-08-30 | redhat |
| redhat | openssh-0:5.3p1-125.el6_10 | 2023-08-02 | redhat |
| redhat | openssh-0:8.0p1-5.el8_1.1 | 2023-08-01 | redhat |
| redhat | openssh-0:8.0p1-5.el8_2 | 2023-08-01 | redhat |
| redhat | openssh-0:8.0p1-15.el8_6 | 2023-08-01 | redhat |
| redhat | openssh-0:8.7p1-30.el9_2 | 2023-08-01 | redhat |
| redhat | openssh-0:7.4p1-23.el7_9 | 2023-08-01 | redhat |
| redhat | openssh-0:8.0p1-7.el8_4 | 2023-08-01 | redhat |
| redhat | openssh-0:8.0p1-19.el8_8 | 2023-08-01 | redhat |
| redhat | openssh-0:8.7p1-11.el9_0 | 2023-07-31 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(7 across 7 ecosystems)
Alpine:v3.16(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| openssh | — |
| — |
Alpine:v3.17(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| openssh | — |
| — |
Debian:10(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| openssh | 1:7.9p1-10, 1:7.9p1-10+deb10u1, 1:7.9p1-10+deb10u2 |
| — |
Debian:11(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| openssh | 1:8.4p1-5, 1:8.4p1-5+deb11u1 |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| openssh | 1:9.2p1-2 |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| openssh | — |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| openssh | — |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(12)
Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.
- Red HatRHSA-2023:4329IMPORTANT2023-07-19
RHSA-2023:4329 — Important
- Red HatRHSA-2023:4381IMPORTANT2023-07-19
RHSA-2023:4381 — Important
- Red HatRHSA-2023:4382IMPORTANT2023-07-19
RHSA-2023:4382 — Important
- Red HatRHSA-2023:4383IMPORTANT2023-07-19
RHSA-2023:4383 — Important
- Red HatRHSA-2023:4384IMPORTANT2023-07-19
RHSA-2023:4384 — Important
- Red HatRHSA-2023:4412IMPORTANT2023-07-19
RHSA-2023:4412 — Important
- Red HatRHSA-2023:4413IMPORTANT2023-07-19
RHSA-2023:4413 — Important
- Red HatRHSA-2023:4419IMPORTANT2023-07-19
RHSA-2023:4419 — Important
- Red HatRHSA-2023:4428IMPORTANT2023-07-19
RHSA-2023:4428 — Important
- Red HatRHSA-2023:4889IMPORTANT2023-07-19
RHSA-2023:4889 — Important
- UbuntuUSN-6242-1MEDIUM
OpenSSH vulnerability
- UbuntuUSN-6242-2MEDIUM
OpenSSH vulnerability
Data Freshness Timeline
(refreshed 25× in last 7d / 52× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 93 of 157 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 7 repeat rows among the latest 100 are merged into the row they repeat. The 64 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-23 16:29 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-10-23 10:36 UTCEG score recompute
- 2026-10-23 10:36 UTCVendor advisory
- 2026-10-23 10:35 UTCGHSA enrichmentGHSA-px36-p9hv-7h2v · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-22 16:31 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-10-22 09:34 UTCEG score recompute
- 2026-10-22 09:34 UTCVendor advisory
- 2026-10-22 09:34 UTCGHSA enrichmentGHSA-px36-p9hv-7h2v · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-21 16:29 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-10-21 08:34 UTCEG score recompute
- 2026-10-21 08:34 UTCVendor advisory
- 2026-10-21 08:34 UTCGHSA enrichmentGHSA-px36-p9hv-7h2v · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-20 16:29 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-10-20 07:35 UTCEG score recompute
- 2026-10-20 07:35 UTCVendor advisory
- 2026-10-20 07:34 UTCGHSA enrichmentGHSA-px36-p9hv-7h2v · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-19 06:35 UTCEG score recompute
- 2026-10-19 06:35 UTCVendor advisory
- 2026-10-19 06:35 UTCGHSA enrichmentGHSA-px36-p9hv-7h2v · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-18 05:37 UTCEG score recompute
- 2026-10-18 05:37 UTCVendor advisory
- 2026-10-18 05:36 UTCGHSA enrichmentGHSA-px36-p9hv-7h2v · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-17 04:38 UTCEG score recompute
- 2026-10-17 04:38 UTCVendor advisory
- 2026-10-17 04:38 UTCGHSA enrichmentGHSA-px36-p9hv-7h2v · GitHub severity CRITICAL · GitHub CVSS 9.8
Show 68 moreShow fewer
- 2026-10-16 03:38 UTCEG score recompute
- 2026-10-16 03:38 UTCVendor advisory
- 2026-10-16 03:38 UTCGHSA enrichmentGHSA-px36-p9hv-7h2v · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-15 16:29 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-10-15 00:27 UTCVendor advisory
- 2026-10-15 00:27 UTCGHSA enrichmentGHSA-px36-p9hv-7h2v · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-14 23:46 UTCVendor advisory
- 2026-10-14 23:46 UTCGHSA enrichmentGHSA-px36-p9hv-7h2v · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-14 22:15 UTCEG score recompute
- 2026-10-14 22:15 UTCVendor advisory
- 2026-10-14 22:15 UTCGHSA enrichmentGHSA-px36-p9hv-7h2v · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-14 16:29 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-10-13 17:54 UTCEG score recompute
- 2026-10-13 17:54 UTCVendor advisory
- 2026-10-13 17:54 UTCGHSA enrichmentGHSA-px36-p9hv-7h2v · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-12 16:55 UTCEG score recompute
- 2026-10-12 16:55 UTCVendor advisory
- 2026-10-12 16:55 UTCGHSA enrichmentGHSA-px36-p9hv-7h2v · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-11 21:48 UTCEG score recompute
- 2026-10-09 22:03 UTCOSV refresh
- 2026-10-09 20:05 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-10-07 23:46 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-10-05 17:41 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-09-30 16:27 UTCEG score recompute
- 2026-09-30 15:01 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-09-26 15:55 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-09-24 14:01 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-09-22 14:45 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-09-20 06:13 UTCOSV refresh
- 2026-09-16 14:05 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-09-12 14:58 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-09-11 14:50 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-09-07 15:59 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-09-06 13:45 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-09-05 15:26 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-09-04 05:04 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-09-02 14:09 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-09-01 09:29 UTCOSV refresh
- 2026-08-30 19:15 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-08-28 21:38 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-08-27 14:23 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-08-25 13:46 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-08-24 14:14 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-08-21 23:47 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-08-19 17:02 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-08-16 02:12 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-08-15 09:07 UTCOSV refresh
- 2026-08-13 21:58 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-08-12 13:48 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-08-06 13:44 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-08-05 19:15 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-08-04 15:07 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-07-30 20:51 UTCOSV refresh
- 2026-07-30 16:26 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-07-28 15:34 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-07-26 14:52 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-07-25 14:16 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-07-24 14:16 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-07-23 02:25 UTCEG score recompute
- 2026-07-22 23:11 UTCEG score recompute
- 2026-07-22 14:06 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-07-21 15:23 UTCEPSS rescoreEPSS 80% · 99th percentile
- 2026-07-20 17:06 UTCEPSS rescoreEPSS 79% · 99th percentile
- 2026-07-19 14:29 UTCEPSS rescoreEPSS 77% · 99th percentile
- 2026-07-16 17:01 UTCEPSS rescoreEPSS 77% · 99th percentile
- 2026-07-15 16:56 UTCEPSS rescoreEPSS 77% · 99th percentile
- 2026-07-15 01:58 UTCEPSS rescoreEPSS 77% · 99th percentile
- 2026-07-13 22:28 UTCEPSS rescoreEPSS 77% · 99th percentile
Publicly available exploits
(5 references)Public exploit code is referenced for this CVE (5 GitHub PoCs). Defenders should treat patch urgency accordingly.
- GitHub PoCAdel2411/cve-2023-38408Published Jul 16, 2025
An in-depth analysis of CVE 2023 38408, a critical OpenSSH vulnerability, including technical background, exploitation in controlled environments, and mitigation strategies.
Open source ↗ - GitHub PoCTX-One/CVE-2023-38408Published Apr 19, 2025
CVE-2023-38408 SSH Vulnerability Scanner & PoC
Open source ↗ - GitHub PoCclassic130/CVE-2023-38408Published Jan 7, 2024
CVE-2023-38408 Remote Code Execution in OpenSSH's forwarded ssh-agent
Open source ↗ - GitHub PoCLucasPDiniz/CVE-2023-38408Published Nov 9, 2023
Takeover Account OpenSSH
Open source ↗ - GitHub PoCkali-mx/CVE-2023-38408Published Aug 9, 2023
PoC for the recent critical vuln affecting OpenSSH versions < 9.3p2
Open source ↗
Related CVEs(same product + same CWE)
Same product
10 shownDebian:10:openssh · Alpine:v3.16:openssh
- CVE-2023-51385NVD 6.5EG 9.8EPSS p97CRITICAL
- CVE-2023-48795NVD 5.9EG 9.0EPSS p100CRITICAL
- CVE-2021-41617EG 7.0HIGH
- CVE-2018-15473NVD 5.3EG 9.0EPSS p100CRITICAL
- CVE-2016-10012EG 7.8HIGH
- CVE-2019-6111NVD 5.9EG 7.5EPSS p99HIGH
- CVE-2016-10009NVD 7.3EG 7.5EPSS p99HIGH
- CVE-2021-28041EG 7.1HIGH
- CVE-2016-10010EG 7.0EPSS p91HIGH
- CVE-2019-6109EG 6.8EPSS p90MEDIUM
Frequently asked(5)
What is CVE-2023-38408?
When was the CVE record for CVE-2023-38408 published?
Is CVE-2023-38408 actively exploited?
What is the CVSS score of CVE-2023-38408?
How do I remediate CVE-2023-38408?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2023-38408
Is Your Infrastructure Affected by CVE-2023-38408?
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