The Go SSH library (x/crypto/ssh) by default does not verify host keys, facilitating man-in-the-middle attacks.
The Go SSH library (x/crypto/ssh) by default does not verify host keys, facilitating man-in-the-middle attacks. Default behavior changed in commit e4e2799 to require explicitly registering a hostkey verification mechanism.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for help- Published
- Apr 4, 2017
- Updated
- Jun 16, 2026
- EPSS
- 3.2% · 87th percentile
- CWE
- CWE-310
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Report tools
Action score
33
Monitor
Low priority for now.
- CVSS
- 32 / 40 · 8.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 3.2%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| golang | crypto | cpe:2.3:a:golang:crypto |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- golang cryptoup to 2017-03-17 inclusive
Versions reported by the vendor
Affected version ranges reported by the assigning authority (certcc). Independent of NVD's CPE analysis and usually ahead of it.
Go SSH library
- prior to commit e4e2799affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | golang-go.crypto | before 1:0.0~git20170407.0.55a552f+REALLY.0.0~git20161012.0.5f31782-1 | 1:0.0~git20170407.0.55a552f+REALLY.0.0~git20161012.0.5f31782-1 |
| Go | golang.org/x/crypto | before 0.0.0-20170330155735-e4e2799dd7aa | 0.0.0-20170330155735-e4e2799dd7aa |
Same product
golang: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-46595Invoking VerifiedPublicKeyCallback permissions skip enforcement in golang.org/x/crypto/ssh40Plan
- CVE-2026-42508Invoking auth bypass via unenforced @revoked status in golang.org/x/crypto/ssh/knownhosts36Monitor
- CVE-2026-39834Invoking infinite loop on large channel writes in golang.org/x/crypto/ssh36Monitor
- CVE-2026-39833Invoking key constraints not enforced in golang.org/x/crypto/ssh/agent36Monitor
- CVE-2026-39832Invoking agent constraints dropped when forwarding keys in golang.org/x/crypto/ssh/agent36Monitor
- CVE-2026-39831Invoking bypass of FIDO/U2F security keys physical interaction in golang.org/x/crypto/ssh36Monitor
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 |
|---|---|---|
| debian:golang-go.crypto | 1:0.0~git20170407.0.55a552f+REALLY.0.0~git20161012.0.5f31782-1 · Debian:12 | Package registry (OSV) |
| Go:golang.org/x/crypto | 0.0.0-20170330155735-e4e2799dd7aa | Package 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.
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.
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.
- No user action is required.
- 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
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-310 · Cryptographic IssuesCVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/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.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- www.securityfocus.com/bid/97481
- bridge.grumpy-troll.org/2017/04/golang-ssh-security/
- github.com/golang/crypto/commit/e4e2799dd7aab89f583e1d898300d96367750991
- github.com/golang/go/issues/19767
- godoc.org/golang.org/x/crypto/ssh
Vendor advisories and official records. Exploit/PoC links are deliberately left out.