CVE-2026-39829: Invoking pathological RSA/DSA parameters may cause DoS in golang.org/x/crypto/ssh
Noroxi assessment
Priority: Monitor (action score 30/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.46% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- According to CISA the attack is automatable: targets can be found by mass scanning.
- Fixed version: golang.org/x/crypto golang.org/x/crypto/ssh 0.52.0; azl3 cert-manager 1.12.15-6 on Azure Linux 3.0 1.12.15-8; azl3 cf-cli 8.7.11-5 on Azure Linux 3.0 8.7.11-6.
Low priority for now. Upgrade to golang.org/x/crypto golang.org/x/crypto/ssh 0.52.0; azl3 cert-manager 1.12.15-6 on Azure Linux 3.0 1.12.15-8; azl3 cf-cli 8.7.11-5 on Azure Linux 3.0 8.7.11-6 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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.
- BDU:2026-07495
- GHSA-w879-237q-wc7r
- ALSA-2026:29455
- ALSA-2026:35833
- ALSA-2026:36199
- ALSA-2026:37123
- GO-2026-5018
- openSUSE-SU-2026:10856-1
- openSUSE-SU-2026:10949-1
- openSUSE-SU-2026:11031-1
- openSUSE-SU-2026:11046-1
- openSUSE-SU-2026:12166-1
- openSUSE-SU-2026:20956-1
- openSUSE-SU-2026:21069-1
- openSUSE-SU-2026:21079-1
- openSUSE-SU-2026:21084-1
- openSUSE-SU-2026:21120-1
- openSUSE-SU-2026:21210-1
- openSUSE-SU-2026:21241-1
- openSUSE-SU-2026:21244-1
- Published
- May 22, 2026
- Updated
- Sep 18, 2026
- EPSS
- 0.4% · 40th percentile
- CWE
- CWE-347
Report tools
Action score
30
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| golang | crypto | cpe:2.3:a:golang:crypto |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- golang cryptobefore 0.52.0
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Go). Independent of NVD's CPE analysis and usually ahead of it.
golang.org/x/crypto golang.org/x/crypto/ssh
- before 0.52.0affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:10 | buildah | before 2:1.43.1-3.el10_2 | 2:1.43.1-3.el10_2 |
| AlmaLinux:10 | buildah-tests | before 2:1.43.1-3.el10_2 | 2:1.43.1-3.el10_2 |
| AlmaLinux:8 | aardvark-dns | before 2:1.10.1-2.module_el8.10.0+3901+4b80ecd7 | 2:1.10.1-2.module_el8.10.0+3901+4b80ecd7 |
| AlmaLinux:8 | aardvark-dns | before 2:1.10.1-2.module_el8.10.0+4089+ce72bbbe | 2:1.10.1-2.module_el8.10.0+4089+ce72bbbe |
| AlmaLinux:8 | aardvark-dns | before 2:1.10.1-2.module_el8.10.0+4047+545787c4 | 2:1.10.1-2.module_el8.10.0+4047+545787c4 |
| AlmaLinux:8 | aardvark-dns | before 2:1.10.1-2.module_el8.10.0+3909+6e1c1eb7 | 2:1.10.1-2.module_el8.10.0+3909+6e1c1eb7 |
| AlmaLinux:8 | buildah | before 2:1.33.14-4.module_el8.10.0+4213+0493256b | 2:1.33.14-4.module_el8.10.0+4213+0493256b |
| AlmaLinux:8 | buildah-tests | before 2:1.33.14-4.module_el8.10.0+4213+0493256b | 2:1.33.14-4.module_el8.10.0+4213+0493256b |
| AlmaLinux:8 | cockpit-podman | before 84.1-1.module_el8.10.0+4102+6c76e544 | 84.1-1.module_el8.10.0+4102+6c76e544 |
| AlmaLinux:8 | conmon | before 3:2.1.10-1.module_el8.10.0+4090+91932338 | 3:2.1.10-1.module_el8.10.0+4090+91932338 |
| AlmaLinux:8 | conmon | before 3:2.1.10-1.module_el8.10.0+4068+0e21408f | 3:2.1.10-1.module_el8.10.0+4068+0e21408f |
| AlmaLinux:8 | conmon | before 3:2.1.10-1.module_el8.10.0+3970+8445edf6 | 3:2.1.10-1.module_el8.10.0+3970+8445edf6 |
| AlmaLinux:8 | container-selinux | before 2:2.229.0-3.module_el8.10.0+4213+0493256b | 2:2.229.0-3.module_el8.10.0+4213+0493256b |
| AlmaLinux:8 | containernetworking-plugins | before 1:1.4.0-8.module_el8.10.0+4136+16425343 | 1:1.4.0-8.module_el8.10.0+4136+16425343 |
| AlmaLinux:8 | containers-common | before 2:1-82.module_el8.10.0+3901+4b80ecd7 | 2:1-82.module_el8.10.0+3901+4b80ecd7 |
| AlmaLinux:8 | containers-common | before 2:1-82.module_el8.10.0+3876+e55593a8 | 2:1-82.module_el8.10.0+3876+e55593a8 |
| AlmaLinux:8 | containers-common | before 2:1-82.module_el8.10.0+4089+ce72bbbe | 2:1-82.module_el8.10.0+4089+ce72bbbe |
| AlmaLinux:8 | crit | before 3.18-5.module_el8.10.0+4047+545787c4 | 3.18-5.module_el8.10.0+4047+545787c4 |
| AlmaLinux:8 | crit | before 3.18-5.module_el8.10.0+3901+4b80ecd7 | 3.18-5.module_el8.10.0+3901+4b80ecd7 |
| AlmaLinux:8 | crit | before 3.18-5.module_el8.10.0+3845+87b84552 | 3.18-5.module_el8.10.0+3845+87b84552 |
| AlmaLinux:8 | crit | before 3.18-5.module_el8.10.0+4120+03ad4b47 | 3.18-5.module_el8.10.0+4120+03ad4b47 |
| AlmaLinux:8 | criu | before 3.18-5.module_el8.10.0+3909+6e1c1eb7 | 3.18-5.module_el8.10.0+3909+6e1c1eb7 |
| AlmaLinux:8 | criu | before 3.18-5.module_el8.10.0+4089+ce72bbbe | 3.18-5.module_el8.10.0+4089+ce72bbbe |
| AlmaLinux:8 | criu | before 3.18-5.module_el8.10.0+4120+03ad4b47 | 3.18-5.module_el8.10.0+4120+03ad4b47 |
+96
Same product
golang: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-46595Invoking VerifiedPublicKeyCallback permissions skip enforcement in golang.org/x/crypto/ssh40Plan
- CVE-2026-42508Invoking auth bypass via unenforced @revoked status in golang.org/x/crypto/ssh/knownhosts38Monitor
- CVE-2026-39834Invoking infinite loop on large channel writes in golang.org/x/crypto/ssh36Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-39827May 22, 2026 · Invoking memory leak when rejecting channels can lead to DoS in golang.org/x/crypto/ssh26Monitor
- ← EarlierCVE-2026-39828May 22, 2026 · Invoking bypass of certificate restrictions in golang.org/x/crypto/ssh25Monitor
- Later →CVE-2026-39830May 22, 2026 · Invoking client can cause server deadlock on unexpected responses in golang.org/x/crypto/ssh36Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| golang.org/x/crypto golang.org/x/crypto/ssh | 0.52.0 | Vendor (CNA) |
| azl3 cert-manager 1.12.15-6 on Azure Linux 3.0 | 1.12.15-8 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 cf-cli 8.7.11-5 on Azure Linux 3.0 | 8.7.11-6 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 docker-buildx 0.14.0-11 on Azure Linux 3.0 | 0.14.0-13 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 docker-compose 2.27.0-9 on Azure Linux 3.0 | 2.27.0-11 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 gh 2.62.0-15 on Azure Linux 3.0 | 2.62.0-16 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 kubernetes 1.30.10-23 on Azure Linux 3.0 | 1.30.10-25 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 kubernetes 1.30.10-25 on Azure Linux 3.0 | 1.30.10-25 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 kubevirt 1.7.1-2 on Azure Linux 3.0 | 1.7.1-5 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 moby-engine 25.0.3-17 on Azure Linux 3.0 | 25.0.3-18 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 moby-engine 25.0.3-18 on Azure Linux 3.0 | 25.0.3-18 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 packer 1.9.5-13 on Azure Linux 3.0 | 1.9.5-14 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 telegraf 1.31.0-19 on Azure Linux 3.0 | 1.31.0-21 · CBL-Mariner Releases | Microsoft (MSRC) |
| almalinux:aardvark-dns | 2:1.10.1-2.module_el8.10.0+3909+6e1c1eb7 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:buildah | 2:1.43.1-2.el9_8 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:buildah-tests | 2:1.43.1-2.el9_8 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:cockpit-podman | 84.1-1.module_el8.10.0+4102+6c76e544 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:conmon | 3:2.1.10-1.module_el8.10.0+3970+8445edf6 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:container-selinux | 2:2.229.0-3.module_el8.10.0+4213+0493256b · AlmaLinux:8 | Package registry (OSV) |
| almalinux:containernetworking-plugins | 1:1.4.0-8.module_el8.10.0+4136+16425343 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:containers-common | 2:1-82.module_el8.10.0+3876+e55593a8 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:crit | 3.18-5.module_el8.10.0+4047+545787c4 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:criu | 3.18-5.module_el8.10.0+4089+ce72bbbe · AlmaLinux:8 | Package registry (OSV) |
| almalinux:criu-devel | 3.18-5.module_el8.10.0+4016+efd18bf8 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:criu-libs | 3.18-5.module_el8.10.0+3970+8445edf6 · AlmaLinux:8 | Package registry (OSV) |
| debian:golang-go.crypto | 1:0.52.0-1 · Debian:14 | Package registry (OSV) |
| Go:golang.org/x/crypto | 0.52.0 | Package registry (OSV) |
| opensuse:alloy | 1.17.0-160000.1.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
| opensuse:amazon-ssm-agent | 3.3.4624.0-160000.1.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
| opensuse:buildah | 1.39.5-160000.2.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
+46
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
No history yet (it accumulates with the daily EPSS job).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-347 · Improper Verification of Cryptographic SignatureCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvd-secondary
Root cause
The verifier takes the algorithm to verify with from the token’s own header. Untrusted data ends up deciding its own verification rule.
The bug in code
The whole CWE-347 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
const claims = jwt.verify(token, publicKey);Fixed
const claims = jwt.verify(token, publicKey, {
algorithms: ["RS256"],
issuer: "https://id.example.com",
audience: "portal",
});Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (19 more)Show less
- go.dev/cl/781661
- go.dev/issue/79565
- groups.google.com/g/golang-announce/c/a082jnz-LvI
- pkg.go.dev/vuln/GO-2026-5018
- access.redhat.com/errata/RHSA-2026:26546
- access.redhat.com/errata/RHSA-2026:26547
- access.redhat.com/errata/RHSA-2026:29455
- access.redhat.com/errata/RHSA-2026:35833
- access.redhat.com/errata/RHSA-2026:36199
- access.redhat.com/errata/RHSA-2026:36207
- access.redhat.com/errata/RHSA-2026:36319
- access.redhat.com/errata/RHSA-2026:36625
- access.redhat.com/errata/RHSA-2026:36648
- access.redhat.com/errata/RHSA-2026:36651
- access.redhat.com/errata/RHSA-2026:36796
- access.redhat.com/errata/RHSA-2026:36797
- access.redhat.com/errata/RHSA-2026:36808
- access.redhat.com/errata/RHSA-2026:36820
- access.redhat.com/errata/RHSA-2026:36883
Vendor advisories and official records. Exploit/PoC links are deliberately left out.