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GHSA-f6x5-jh6r-wrfv CVE-2025-47914 GO-2025-4135

golang.org/x/crypto/ssh/agent vulnerable to panic if message is malformed due to out of bounds read

Medium Go
Severity
5.3 / 10
Medium · CVSS 3.1
Exploit chance (EPSS)
0.55%
Chance of exploitation in the next 30 days. Higher than 45.82% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-125 Out-of-bounds Read
Fix
0.45.0
Upgrade golang.org/x/crypto to this version or later

Description

SSH Agent servers do not validate the size of messages when processing new identity requests, which may cause the program to panic if the message is malformed due to an out of bounds read.

Affected versions

Go

PackageVulnerableFixed in
golang.org/x/crypto
< 0.45.0
0.45.0
golang.org/x/crypto
< 0.45.0
0.45.0

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 → 0.45.0

go
go get golang.org/x/crypto@v0.45.0 && go mod tidy

Severity breakdown

CVSS 3.1 5.3

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

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

Weakness

CWE-125: Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

How to prevent it
  • Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.
  • Architecture and Design: Use a language that provides appropriate memory abstractions.

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy 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, leonklingele

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