CVE-2026-39829 | Invoking pathological RSA/DSA parameters may cause DoS in golang.org/x/crypto/ssh

The RSA and DSA public key parsers did not enforce size limits on key parameters. A crafted public key with an excessively large modulus or DSA parameter could cause several minutes of CPU consumption during signature verification. This could be triggered by unauthenticated clients during public key authentication. RSA moduli are now limited to 8192 bits, and DSA parameters are validated per FIPS 186-2.

Published: 2026-05-22 Last update: 2026-06-02 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-39829 is rated Low Risk (36.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.28%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2026-39829

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 2026-06-15 0.03% 0.28% +0.24%
2 2026-06-03 0.07% 0.03% -0.04%
3 2026-05-23 0.07%

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-39829

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H 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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-39829

OS Trackers for CVE-2026-39829

vendor priority summary link
debian not yet assigned CVE-2026-39829 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-2026-39829
suse high https://www.suse.com/security/cve/CVE-2026-39829/
ubuntu medium CVE-2026-39829 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 26, DNE 4, not-affected 1. https://ubuntu.com/security/CVE-2026-39829

Affected software / configurations for CVE-2026-39829

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

References for CVE-2026-39829

cvelogic Threat Intelligence