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NVD / CVE Program· CNA Linux

CVE-2026-64306: crypto: drbg - Fix returning success on failure in CTR_DRBG

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.16% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 074db6db03a0aaa78f05ca9d4838053713796665, 23b8b188cb32e5531d0f8d3af9506f8959cb369e, 3.13; azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 6.6.145.2-1.

Low priority for now. Upgrade to Linux Linux 074db6db03a0aaa78f05ca9d4838053713796665, 23b8b188cb32e5531d0f8d3af9506f8959cb369e, 3.13; azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 6.6.145.2-1 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

In the Linux kernel, the following vulnerability has been resolved: crypto: drbg - Fix returning success on failure in CTR_DRBG drbg_ctr_generate() sometimes returns success when it fails, leaving the output buffer uninitialized. Fix it.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Jul 25, 2026
Updated
Oct 24, 2026
EPSS
0.1% · 5th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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.

Follow CVE-2026-64306

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

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Affected 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.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel3.12.44 and later · before 3.13
  • linux linux kernel4.1 and later · before 5.10.261
  • linux linux kernel5.11 and later · before 5.15.212
  • linux linux kernel5.16 and later · before 6.1.178
  • linux linux kernel6.2 and later · before 6.6.145
  • linux linux kernel6.7 and later · before 6.12.96
  • linux linux kernel6.13 and later · before 6.18.39
  • linux linux kernel6.19 and later · before 7.1.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • f60b0fa8bbddde66f1d197be07120264b555c84a, 4.1affected
    • cde001e4c3c3625c60b68a83eb1f1c2572dee07a and later · before 074db6db03a0aaa78f05ca9d4838053713796665affected · git
    • cde001e4c3c3625c60b68a83eb1f1c2572dee07a and later · before 7b03312491f9fe6ba4d60c4023e7e61d2d1fed96affected · git
    • cde001e4c3c3625c60b68a83eb1f1c2572dee07a and later · before 75597e8774f319152744d24e0683d9393540a951affected · git
    • cde001e4c3c3625c60b68a83eb1f1c2572dee07a and later · before cc42fb40171c249bb859071d81b4eb007398a0bcaffected · git
    • cde001e4c3c3625c60b68a83eb1f1c2572dee07a and later · before bbbac12083eff489b35d848332f0dff311131344affected · git
    • cde001e4c3c3625c60b68a83eb1f1c2572dee07a and later · before 23b8b188cb32e5531d0f8d3af9506f8959cb369eaffected · git
    • cde001e4c3c3625c60b68a83eb1f1c2572dee07a and later · before a9e886f73dd717027028bb7e3bbca93601ecdfc7affected · git
    • cde001e4c3c3625c60b68a83eb1f1c2572dee07a and later · before 39a31ad9e2a5ed7e9c9c6f711dca96c8c8f5f26baffected · git
    • 3.12.44 and later · before 3.13affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.180-16.1.180-1
Debian:12linux-6.12before 6.12.100-1~deb12u16.12.100-1~deb12u1
Debian:13linuxbefore 6.12.96-16.12.96-1
Debian:14linuxbefore 7.1.4-17.1.4-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-64304Jul 25, 2026 · crypto: qat - validate RSA CRT component lengths
    31Monitor
  • ← EarlierCVE-2026-64305Jul 25, 2026 · crypto: qat - protect service table iterations with service_lock
    31Monitor
  • Later →CVE-2026-64307Jul 25, 2026 · crypto: ccp - Do not initialize SNP for ioctl(SNP_CONFIG)
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux074db6db03a0aaa78f05ca9d4838053713796665Vendor (CNA)
Linux Linux23b8b188cb32e5531d0f8d3af9506f8959cb369eVendor (CNA)
Linux Linux3.13Vendor (CNA)
Linux Linux39a31ad9e2a5ed7e9c9c6f711dca96c8c8f5f26bVendor (CNA)
Linux Linux75597e8774f319152744d24e0683d9393540a951Vendor (CNA)
Linux Linux7b03312491f9fe6ba4d60c4023e7e61d2d1fed96Vendor (CNA)
Linux Linuxa9e886f73dd717027028bb7e3bbca93601ecdfc7Vendor (CNA)
Linux Linuxbbbac12083eff489b35d848332f0dff311131344Vendor (CNA)
Linux Linuxcc42fb40171c249bb859071d81b4eb007398a0bcVendor (CNA)
azl3 kernel 6.6.144.1-1 on Azure Linux 3.06.6.145.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.180-1 · Debian:12Package registry (OSV)
debian:linux-6.126.12.100-1~deb12u1 · Debian:12Package registry (OSV)

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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

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 researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

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

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • 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
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records