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NVD / CVE Program· CNA Linux

CVE-2025-40204: sctp: Fix MAC comparison to be constant-time

Noroxi assessment

Priority: Monitor (action score 32/100)

  • 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. Special conditions such as timing or configuration are required.
  • Fixed version: Linux Linux 0b32ff285ff6f6f1ac1d9495787ccce8837d6405, 0e8b8c326c2a6de4d837b1bb034ea704f4690d77, 1cd60e0d0fb8f0e62ec4499138afce6342dc9d4c; azl3 kernel 6.6.112.1-2 on Azure Linux 3.0 6.6.117.1-1.

Low priority for now. Upgrade to Linux Linux 0b32ff285ff6f6f1ac1d9495787ccce8837d6405, 0e8b8c326c2a6de4d837b1bb034ea704f4690d77, 1cd60e0d0fb8f0e62ec4499138afce6342dc9d4c; azl3 kernel 6.6.112.1-2 on Azure Linux 3.0 6.6.117.1-1 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: sctp: Fix MAC comparison to be constant-time To prevent timing attacks, MACs need to be compared in constant time. Use the appropriate helper function for this.

HighCVSS 8.1 · v3.1—No exploit Fix available
Published
Nov 12, 2025
Updated
Oct 19, 2026
EPSS
0.4% · 40th percentile
CWE
—

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
8.1
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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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When you'll hear from us

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  • when exploit code appears or is weaponized
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  • 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.

—

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

    • 2.6.12affected
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before b93fa8dc521d00d2d44bf034fb90e0d79b036617affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 0e8b8c326c2a6de4d837b1bb034ea704f4690d77affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 1cd60e0d0fb8f0e62ec4499138afce6342dc9d4caffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 9c05d44ec24126fc283835b68f82dba3ae985209affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before ed3044b9c810c5c24eb2830053fbfe5fd134c5d4affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 8019b3699289fce3f10b63f98601db97b8d105b0affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 0b32ff285ff6f6f1ac1d9495787ccce8837d6405affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before dd91c79e4f58fbe2898dac84858033700e0e99fbaffected · git
    • before 2.6.12not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.158-16.1.158-1
Debian:13linuxbefore 6.12.57-16.12.57-1
Debian:14linuxbefore 6.17.6-16.17.6-1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-64kbbefore 5.3.18-150300.59.229.35.3.18-150300.59.229.3
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-default-basebefore 5.3.18-150300.59.229.3.150300.18.136.35.3.18-150300.59.229.3.150300.18.136.3
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-docsbefore 5.3.18-150300.59.229.25.3.18-150300.59.229.2
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-obs-buildbefore 5.3.18-150300.59.229.35.3.18-150300.59.229.3
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-preemptbefore 5.3.18-150300.59.229.35.3.18-150300.59.229.3
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-sourcebefore 5.3.18-150300.59.229.35.3.18-150300.59.229.3
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-symsbefore 5.3.18-150300.59.229.15.3.18-150300.59.229.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSkernel-64kbbefore 5.14.21-150400.24.187.35.14.21-150400.24.187.3
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSkernel-docsbefore 5.14.21-150400.24.187.15.14.21-150400.24.187.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSkernel-obs-buildbefore 5.14.21-150400.24.187.35.14.21-150400.24.187.3
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSkernel-sourcebefore 5.14.21-150400.24.187.35.14.21-150400.24.187.3
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSkernel-symsbefore 5.14.21-150400.24.187.15.14.21-150400.24.187.1
SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSkernel-64kbbefore 5.14.21-150500.55.130.35.14.21-150500.55.130.3
SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSkernel-docsbefore 5.14.21-150500.55.130.15.14.21-150500.55.130.1
SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSkernel-obs-buildbefore 5.14.21-150500.55.130.35.14.21-150500.55.130.3
SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSkernel-symsbefore 5.14.21-150500.55.130.15.14.21-150500.55.130.1
SUSE:Linux Enterprise Live Patching 12 SP5kgraft-patch-SLE12-SP5_Update_63before 16-2.116-2.1
SUSE:Linux Enterprise Live Patching 12 SP5kgraft-patch-SLE12-SP5_Update_71before 17-2.117-2.1
SUSE:Linux Enterprise Live Patching 12 SP5kgraft-patch-SLE12-SP5_Update_72before 4-2.14-2.1
SUSE:Linux Enterprise Live Patching 12 SP5kgraft-patch-SLE12-SP5_Update_72before 16-2.116-2.1
SUSE:Linux Enterprise Live Patching 12 SP5kgraft-patch-SLE12-SP5_Update_73before 2-2.12-2.1

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2025-40202Nov 12, 2025 · ipmi: Rework user message limit handling
    31Monitor
  • ← EarlierCVE-2025-40203Nov 12, 2025 · listmount: don't call path_put() under namespace semaphore
    31Monitor
  • Later →CVE-2025-40205Nov 12, 2025 · btrfs: avoid potential out-of-bounds in btrfs_encode_fh()
    31Monitor

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 Linux0b32ff285ff6f6f1ac1d9495787ccce8837d6405Vendor (CNA)
Linux Linux0e8b8c326c2a6de4d837b1bb034ea704f4690d77Vendor (CNA)
Linux Linux1cd60e0d0fb8f0e62ec4499138afce6342dc9d4cVendor (CNA)
Linux Linux8019b3699289fce3f10b63f98601db97b8d105b0Vendor (CNA)
Linux Linux9c05d44ec24126fc283835b68f82dba3ae985209Vendor (CNA)
Linux Linuxb93fa8dc521d00d2d44bf034fb90e0d79b036617Vendor (CNA)
Linux Linuxdd91c79e4f58fbe2898dac84858033700e0e99fbVendor (CNA)
Linux Linuxed3044b9c810c5c24eb2830053fbfe5fd134c5d4Vendor (CNA)
azl3 kernel 6.6.112.1-2 on Azure Linux 3.06.6.117.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.158-1 · Debian:12Package registry (OSV)
suse:kernel-64kb5.14.21-150500.55.130.3 · SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSPackage registry (OSV)
suse:kernel-default5.14.21-150500.55.130.3 · SUSE:Linux Enterprise Micro 5.5Package registry (OSV)
suse:kernel-default-base5.14.21-150500.55.130.3.150500.6.63.3 · SUSE:Linux Enterprise Micro 5.5Package registry (OSV)
suse:kernel-docs5.14.21-150500.55.130.1 · SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSPackage registry (OSV)
suse:kernel-livepatch-SLE15-SP3_Update_641-150300.7.3.3 · SUSE:Linux Enterprise Live Patching 15 SP3Package registry (OSV)
suse:kernel-livepatch-SLE15-SP4_Update_471-150400.9.3.3 · SUSE:Linux Enterprise Live Patching 15 SP4Package registry (OSV)
suse:kernel-livepatch-SLE15-SP5_Update_331-150500.11.3.3 · SUSE:Linux Enterprise Live Patching 15 SP5Package registry (OSV)
suse:kernel-obs-build5.14.21-150500.55.130.3 · SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSPackage registry (OSV)
suse:kernel-preempt5.3.18-150300.59.229.3 · SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSPackage registry (OSV)
suse:kernel-source5.14.21-150500.55.130.3 · SUSE:Linux Enterprise Micro 5.5Package registry (OSV)
suse:kernel-syms5.14.21-150500.55.130.1 · SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSPackage registry (OSV)
suse:kernel-zfcpdump5.14.21-150500.55.130.3 · SUSE:Linux Enterprise Server 15 SP5-LTSSPackage 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.

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 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

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-secondary

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. SSVC exploitation— → none
  2. 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