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CVE.org (no NVD analysis yet)· CNA Linux

CVE-2026-99165: sctp: revalidate output stream after association connect wait

Noroxi assessment

Priority: Monitor (action score 0/100)

  • 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: 0.18% (FIRST EPSS).
  • Fixed version: Linux Linux 26af2969b29cc5eb893a454fee2a36b39521a5bd, 504bdf55438ad4b1ecbfba0f7fe95e1933f7fb66, 77a63d1b813b08c4e5a948f5e04fbaca6176aa8f; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 Release Notes.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 26af2969b29cc5eb893a454fee2a36b39521a5bd, 504bdf55438ad4b1ecbfba0f7fe95e1933f7fb66, 77a63d1b813b08c4e5a948f5e04fbaca6176aa8f; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 Release Notes 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: revalidate output stream after association connect wait When message interleaving is enabled, the first send waits for association establishment before building its data chunks. The wait drops the socket lock, and handshake processing can reduce the output stream count to the peer-advertised inbound stream count. sctp_stream_init() then frees the extension of every removed stream. The sender resumes with the stream that it checked before the wait. If the peer removed that stream, sctp_outq_tail() later dereferences its NULL extension. Fatal-oops policies then panic the host. KASAN: null-ptr-deref in range [0x38-0x3f] RIP: sctp_outq_tail+0x49e/0xaa0 Call Trace: sctp_primitive_SEND sctp_sendmsg_to_asoc sctp_sendmsg A range check alone is insufficient. Stream reconfiguration can grow the output count again while the lock is released without recreating extensions freed by the earlier shrink. The stream can then be in range while its extension remains NULL. The send-buffer wait has the same issue. Factor the range and extension checks into a helper and repeat both after each send-path wait that drops the socket lock. Once the lock is reacquired, the validation remains stable through data creation and queueing. If validation fails after the connect wait, the auto-created association is already established. Return ESRCH so the existing caller path keeps it under state-machine ownership instead of freeing it directly, which would leave protocol, counter and socket state inconsistent.

—No exploit Fix available
Published
Oct 28, 2026
Updated
Oct 30, 2026
EPSS
0.1% · 7th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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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

    • 4.16affected
    • 668c9beb9020d5834ee9e43c208190a07d2b1928 and later · before 26af2969b29cc5eb893a454fee2a36b39521a5bdaffected · git
    • 668c9beb9020d5834ee9e43c208190a07d2b1928 and later · before b925652ba3a3ee11b2617e68de92379144b5b84baffected · git
    • 668c9beb9020d5834ee9e43c208190a07d2b1928 and later · before 504bdf55438ad4b1ecbfba0f7fe95e1933f7fb66affected · git
    • 668c9beb9020d5834ee9e43c208190a07d2b1928 and later · before 994694a2d4611d7b76cf05ff401a92b1c0451e1faffected · git
    • 668c9beb9020d5834ee9e43c208190a07d2b1928 and later · before 84f741b7bb3974e674c9739055826aa040362bbaaffected · git
    • 668c9beb9020d5834ee9e43c208190a07d2b1928 and later · before 77a63d1b813b08c4e5a948f5e04fbaca6176aa8faffected · git
    • 668c9beb9020d5834ee9e43c208190a07d2b1928 and later · before fd56ac95ec31a05b66e8938debfa847f49c0e993affected · git
    • 668c9beb9020d5834ee9e43c208190a07d2b1928 and later · before b7ad72414c673ce1fa1f463e807cd4f34f8be9bfaffected · git
    • before 4.16not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:13linuxbefore 6.12.115-26.12.115-2

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-2026-99163Oct 28, 2026 · tracing/histograms: Reject non-stacktrace fields for synthetic stacktrace fields
    31Monitor
  • ← EarlierCVE-2026-99164Oct 28, 2026 · spi: imx: fix slab corruption from undersized DMA bounce buffers
    31Monitor
  • Later →CVE-2026-99166Oct 28, 2026 · net: rds: fix uninitialized trans dereference in CM event handler
    0Monitor

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 Linux26af2969b29cc5eb893a454fee2a36b39521a5bdVendor (CNA)
Linux Linux504bdf55438ad4b1ecbfba0f7fe95e1933f7fb66Vendor (CNA)
Linux Linux77a63d1b813b08c4e5a948f5e04fbaca6176aa8fVendor (CNA)
Linux Linux84f741b7bb3974e674c9739055826aa040362bbaVendor (CNA)
Linux Linux994694a2d4611d7b76cf05ff401a92b1c0451e1fVendor (CNA)
Linux Linuxb7ad72414c673ce1fa1f463e807cd4f34f8be9bfVendor (CNA)
Linux Linuxb925652ba3a3ee11b2617e68de92379144b5b84bVendor (CNA)
Linux Linuxfd56ac95ec31a05b66e8938debfa847f49c0e993Vendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kernel 6.6.159.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
debian:linux6.12.115-2 · Debian:13Package 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.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 5, 2026+8 d
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

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

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. Exploit maturity— → 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