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NVD / CVE Program· CNA Linux

CVE-2026-89479: sctp: stop processing a packet once its association is deleted

Noroxi assessment

Priority: Monitor (action score 39/100)

  • 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: 0.50% (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: Linux Linux 09c3b193a3e8fe53e1f416e2f8e3283d2a785405, 47e15a8d12e366d0d261bcbc394394f44418938d, 5c0b2dbbdafc9eeeb11fffe1e46551fc3b55d8ee; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 09c3b193a3e8fe53e1f416e2f8e3283d2a785405, 47e15a8d12e366d0d261bcbc394394f44418938d, 5c0b2dbbdafc9eeeb11fffe1e46551fc3b55d8ee; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1 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: stop processing a packet once its association is deleted sctp_endpoint_bh_rcv() looks the association up only when chunk->asoc is NULL, and caches the result in chunk->asoc and chunk->transport without taking a reference. A packet that matches no association is handed to the endpoint, so a peer can bundle COOKIE ECHO, SHUTDOWN and SHUTDOWN ACK in one packet. The COOKIE ECHO creates the association, the SHUTDOWN chunk caches it, and with the outqueue empty the SHUTDOWN ACK reaches sctp_sf_do_9_2_final(), so the association and its transports are freed. The endpoint loop has no counterpart to the asoc->base.dead check in sctp_assoc_bh_rcv(). The next chunk writes to last_time_heard in the freed transport and is then passed to sctp_do_sm() with the freed association. The transport is freed through RCU, so this needs the packet to come off the socket backlog, where the loop runs in task context. The endpoint loop cannot do the same check: it holds no reference on the association, so reading asoc->base.dead would itself be a use-after-free. Mark the packet for discard in the command interpreter, just before it deletes the association. That is also before sctp_inq_free() releases the chunk on the association receive path. sctp_sf_do_5_2_4_dupcook() issues SCTP_CMD_DELETE_TCB for the temporary association, while the one the packet belongs to stays alive. A restarting peer can bundle DATA behind its COOKIE ECHO, so compare against chunk->asoc and leave that case alone.

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Sep 11, 2026
Updated
Oct 19, 2026
EPSS
0.5% · 43th percentile
CWE
—

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
9.8
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.

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  • Not in KEV: no record of exploitation in the wild
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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 7d970353eeb98f46a3b9dc602850e4f6336a9889affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 09c3b193a3e8fe53e1f416e2f8e3283d2a785405affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before ed85fe91a61bc0e0da6b585c07102b20f4cc65a0affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 5c0b2dbbdafc9eeeb11fffe1e46551fc3b55d8eeaffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before ee3f04cf566f6041aa9a0360494fd8db5ade383aaffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before fa306a40e716c5abcd967475459ce1ebd56e5115affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before a713e1b3a265f180ad25a08e17be15d67a2f7149affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 47e15a8d12e366d0d261bcbc394394f44418938daffected · 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
AlmaLinux:8bpftoolbefore 4.18.0-553.176.1.el8_104.18.0-553.176.1.el8_10
AlmaLinux:8kernelbefore 4.18.0-553.176.1.el8_104.18.0-553.176.1.el8_10
AlmaLinux:8kernel-abi-stablelistsbefore 4.18.0-553.176.1.el8_104.18.0-553.176.1.el8_10
AlmaLinux:8kernel-corebefore 4.18.0-553.176.1.el8_104.18.0-553.176.1.el8_10
AlmaLinux:8kernel-cross-headersbefore 4.18.0-553.176.1.el8_104.18.0-553.176.1.el8_10
AlmaLinux:8kernel-debugbefore 4.18.0-553.176.1.el8_104.18.0-553.176.1.el8_10
AlmaLinux:8kernel-debug-corebefore 4.18.0-553.176.1.el8_104.18.0-553.176.1.el8_10
AlmaLinux:8kernel-debug-develbefore 4.18.0-553.176.1.el8_104.18.0-553.176.1.el8_10
AlmaLinux:8kernel-debug-modulesbefore 4.18.0-553.176.1.el8_104.18.0-553.176.1.el8_10
AlmaLinux:8kernel-debug-modules-extrabefore 4.18.0-553.176.1.el8_104.18.0-553.176.1.el8_10
AlmaLinux:8kernel-develbefore 4.18.0-553.176.1.el8_104.18.0-553.176.1.el8_10
AlmaLinux:8kernel-docbefore 4.18.0-553.176.1.el8_104.18.0-553.176.1.el8_10
AlmaLinux:8kernel-headersbefore 4.18.0-553.176.1.el8_104.18.0-553.176.1.el8_10
AlmaLinux:8kernel-modulesbefore 4.18.0-553.176.1.el8_104.18.0-553.176.1.el8_10
AlmaLinux:8kernel-modules-extrabefore 4.18.0-553.176.1.el8_104.18.0-553.176.1.el8_10
AlmaLinux:8kernel-rtbefore 4.18.0-553.176.1.rt7.517.el8_104.18.0-553.176.1.rt7.517.el8_10
AlmaLinux:8kernel-rt-corebefore 4.18.0-553.176.1.rt7.517.el8_104.18.0-553.176.1.rt7.517.el8_10
AlmaLinux:8kernel-rt-debugbefore 4.18.0-553.176.1.rt7.517.el8_104.18.0-553.176.1.rt7.517.el8_10
AlmaLinux:8kernel-rt-debug-corebefore 4.18.0-553.176.1.rt7.517.el8_104.18.0-553.176.1.rt7.517.el8_10
AlmaLinux:8kernel-rt-debug-develbefore 4.18.0-553.176.1.rt7.517.el8_104.18.0-553.176.1.rt7.517.el8_10
AlmaLinux:8kernel-rt-debug-modulesbefore 4.18.0-553.176.1.rt7.517.el8_104.18.0-553.176.1.rt7.517.el8_10
AlmaLinux:8kernel-rt-debug-modules-extrabefore 4.18.0-553.176.1.rt7.517.el8_104.18.0-553.176.1.rt7.517.el8_10
AlmaLinux:8kernel-rt-develbefore 4.18.0-553.176.1.rt7.517.el8_104.18.0-553.176.1.rt7.517.el8_10
AlmaLinux:8kernel-rt-modulesbefore 4.18.0-553.176.1.rt7.517.el8_104.18.0-553.176.1.rt7.517.el8_10

+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-2026-89477Sep 11, 2026 · sctp: fix NULL deref on untransmitted RECONF completion
    30Monitor
  • ← EarlierCVE-2026-89478Sep 11, 2026 · sctp: drop a chunk if its transport was removed
    39Monitor
  • Later →CVE-2026-89480Sep 11, 2026 · nvme-tcp: reject a read that transferred too few bytes
    30Monitor

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 Linux09c3b193a3e8fe53e1f416e2f8e3283d2a785405Vendor (CNA)
Linux Linux47e15a8d12e366d0d261bcbc394394f44418938dVendor (CNA)
Linux Linux5c0b2dbbdafc9eeeb11fffe1e46551fc3b55d8eeVendor (CNA)
Linux Linux7d970353eeb98f46a3b9dc602850e4f6336a9889Vendor (CNA)
Linux Linuxa713e1b3a265f180ad25a08e17be15d67a2f7149Vendor (CNA)
Linux Linuxed85fe91a61bc0e0da6b585c07102b20f4cc65a0Vendor (CNA)
Linux Linuxee3f04cf566f6041aa9a0360494fd8db5ade383aVendor (CNA)
Linux Linuxfa306a40e716c5abcd967475459ce1ebd56e5115Vendor (CNA)
azl3 kernel 6.6.150.1-1 on Azure Linux 3.0—Microsoft (MSRC)
azl3 kernel 6.6.152.1-1 on Azure Linux 3.06.6.157.1-1 · Release NotesMicrosoft (MSRC)
almalinux:bpftool4.18.0-553.176.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-553.176.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-abi-stablelists4.18.0-553.176.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-core4.18.0-553.176.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-cross-headers4.18.0-553.176.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug4.18.0-553.176.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-core4.18.0-553.176.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-devel4.18.0-553.176.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules4.18.0-553.176.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules-extra4.18.0-553.176.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-devel4.18.0-553.176.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-doc4.18.0-553.176.1.el8_10 · AlmaLinux:8Package registry (OSV)
debian:linux6.1.190-1 · Debian:12Package registry (OSV)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package registry (OSV)
red hat:bpftool0:4.18.0-553.176.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:bpftool-debuginfo0:4.18.0-553.176.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel0:4.18.0-553.176.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-abi-stablelists0:4.18.0-553.176.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-core0:4.18.0-553.176.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)

+16

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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

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
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
Low
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:L/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