CyberSecBulletin
CVE-2026-39832NVD status: Modified

golang.org/x/crypto/ssh/agent: Deserialization of Untrusted Data

Published Updated By the CyberSecBulletin desk

CVE-2026-39832 is a high-severity deserialization of untrusted data vulnerability in golang.org/x/crypto/ssh/agent from Golang.org/x/crypto, with a CVSS 3.1 base score of 8.7 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. The record lists version 0.52.0 as the first without the flaw, so updating golang.org/x/crypto/ssh/agent to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.68% chance of exploitation within 30 days, higher than 53% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update golang.org/x/crypto/ssh/agent to 0.52.0 or a later version.
  2. Update Crypto to 0.52.0 or a later version.
  3. Read the advisory on pkg.go.dev for workarounds and exact fixed builds.
  4. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
Golang.org/x/cryptogolang.org/x/crypto/ssh/agentbefore 0.52.00.52.0
Red HatRed Hat Enterprise Linux 10Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update ServiceNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8.8 Update Services for SAP SolutionsNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9Not specified in the recordNot stated
Red HatRHEM 1.0 for RHEL 9Not specified in the recordNot stated
Red HatRHEM 1.1 for RHEL 10Not specified in the recordNot stated
Red HatRHEM 1.1 for RHEL 9Not specified in the recordNot stated
Red HatCluster Observability Operator 1.5.0Not specified in the recordNot stated
Red HatLogging Subsystem for Red Hat OpenShift 6.6Not specified in the recordNot stated
Red Hatmulticluster engine for Kubernetes 2.11Not specified in the recordNot stated
Red Hatmulticluster engine for Kubernetes 2.6Not specified in the recordNot stated
Red HatOpenShift API for Data Protection 1.6Not specified in the recordNot stated
Red HatRed Hat Advanced Cluster Security 4.9Not specified in the recordNot stated
Red HatRed Hat Advanced Cluster Security for Kubernetes 4.10Not specified in the recordNot stated
Red HatRed Hat Edge Manager 1.0Not specified in the recordNot stated
Red HatRed Hat Edge Manager 1.1Not specified in the recordNot stated
Red HatRed Hat OpenShift Builds 1.7.3Not specified in the recordNot stated
Red HatRed Hat OpenShift Builds 1.8.1Not specified in the recordNot stated
Red HatRed Hat Openshift Data Foundation 4.22Not specified in the recordNot stated
Red HatRed Hat OpenShift GitOps 1.19Not specified in the recordNot stated
Red HatRed Hat OpenShift GitOps 1.20Not specified in the recordNot stated
Red HatRed Hat Quay 3.10Not specified in the recordNot stated
Red HatRed Hat Quay 3.12Not specified in the recordNot stated

Version data comes from the organisation that assigned the CVE; 24 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N. Scored by CNA.

Scoring systemScoreSeverityScored by
CVSS 3.19.1CriticalCISA (ADP)
CVSS 3.18.7HighCNA

Official description

When adding a key to a remote agent constraint extensions such as [email protected] were not serialized in the request. Destination restrictions were silently stripped when forwarding keys, allowing unrestricted use of the key on the remote host. The client now serializes all constraint extensions. Additionally, the in-memory keyring returned by NewKeyring() now rejects keys with unsupported constraint extensions instead of silently ignoring them.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Deserialization of Untrusted Data

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

How developers prevent this class of flaw

  • If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
  • When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
  • Explicitly define a final object() to prevent deserialization.

More Deserialization of Untrusted Data vulnerabilities (CWE-502)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in golang.org/x/crypto/ssh/agent

All golang.org/x/crypto/ssh/agent vulnerabilities

Recent Deserialization of Untrusted Data vulnerabilities

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