GO-2025-4116 CVE-2025-47913 GHSA-56w8-48fp-6mgv
Potential denial of service in golang.org/x/crypto/ssh/agent
- Severity
- 7.5 / 10
- High · CVSS 3.1
- Exploit chance (EPSS)
- 0.67%
- Chance of exploitation in the next 30 days. Higher than 51.91% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-617 Reachable Assertion
- Fix
- Available
- 2 packages have a fixed version
Description
SSH clients receiving SSH_AGENT_SUCCESS when expecting a typed response will panic and cause early termination of the client process.
Affected versions
Go
| Package | Vulnerable | Fixed in |
|---|---|---|
| golang.org/x/crypto | < 0.43.0 |
0.43.0 |
| golang.org/x/crypto/ssh/agent | < 0.43.0 |
0.43.0 |
| golang.org/x/crypto/ssh/agent | < 0.43.0 |
0.43.0 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
golang.org/x/crypto Go → 0.43.0
- go
go get golang.org/x/crypto@v0.43.0 && go mod tidy
golang.org/x/crypto/ssh/agent Go → 0.43.0
- go
go get golang.org/x/crypto/ssh/agent@v0.43.0 && go mod tidy
Severity breakdown
CVSS 3.1 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Weakness
CWE-617: Reachable Assertion
The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.
How to prevent it
- Implementation: Make sensitive open/close operation non reachable by directly user-controlled data (e.g. open/close resources)
- Implementation: Perform input validation on user data.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GO-2026-6355 Prevent DoS on deadlocked established channel in golang.org/x/crypto/ssh | High | Also affects golang.org/x/crypto |
| GO-2026-6354 Prevent DoS on deadlocked undecided channel in golang.org/x/crypto/ssh | High | Also affects golang.org/x/crypto |
| GO-2026-6303 Source-address critical option not enforced for non-public-key auth callbacks in golang.org/x/crypto/ssh | High | Also affects golang.org/x/crypto |
| GO-2026-5932 The golang.org/x/crypto/openpgp package is unmaintained, unsafe by design, and has known security issues | Not rated yet | Also affects golang.org/x/crypto |
| GHSA-x527-x647-q7gg golang.org/x/crypto: Invoking VerifiedPublicKeyCallback permissions skip enforcement | Critical | Also affects golang.org/x/crypto |
| GHSA-w879-237q-wc7r golang.org/x/crypto: Invoking pathological RSA/DSA parameters may cause DoS | High | Also affects golang.org/x/crypto |
| GHSA-vgwf-h737-ff37 golang.org/x/crypto: Invoking client can cause server deadlock on unexpected responses | Critical | Also affects golang.org/x/crypto |
| GHSA-rm3j-f69w-wqmq golang.org/x/crypto vulnerable to infinite loop on large channel writes | Critical | Also affects golang.org/x/crypto |
Credits: Jakub Ciolek, Nicola Murino, augustocesarperin
MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.
Check your repos with MergeHarbor