CVE-2026-39832 | Invoking agent constraints dropped when forwarding keys in golang.org/x/crypto/ssh/agent

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.

Published: 2026-05-22 Last update: 2026-05-28 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-39832 is rated Moderate Risk (43.8/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.07%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-39832

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-29 0.02% 0.07% +0.05%
2 2026-05-22 — 0.02% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-39832

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.1 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 5.2 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-39832

OS Trackers for CVE-2026-39832

vendor priority summary link
debian not yet assigned CVE-2026-39832 not yet assigned priority: Debian including 1 source packages (golang-go.crypto), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. https://security-tracker.debian.org/tracker/CVE-2026-39832
suse high — https://www.suse.com/security/cve/CVE-2026-39832/
ubuntu medium CVE-2026-39832 medium priority: Ubuntu including 4 source packages (golang-go.crypto, google-guest-agent, lxd, snapd), 31 status rows across 8 suites (bionic, focal, jammy, noble, questing, resolute, upstream, xenial): needs-triage 18, needed 7, DNE 4, not-affected 1, released 1. https://ubuntu.com/security/CVE-2026-39832

Affected software / configurations for CVE-2026-39832

Vendor Product Version Raw CPE
golang crypto < 0.52.0 cpe:2.3:a:golang:crypto:*:*:*:*:*:go:*:*

References for CVE-2026-39832

cvelogic Threat Intelligence