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NVD / CVE Program· CNA Linux

CVE-2026-64551: sctp: validate STALE_COOKIE cause length before reading staleness

CriticalCVSS 9.1 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 36/100)

  • 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: 0.51% (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 08a8f2d13f703924316e9aeac863a88ef50990c7, 1cd23ca80784223fa2204e16203f754da4e821f8, 588706ebaf8cdb4a4161602949eba365514b1db1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 08a8f2d13f703924316e9aeac863a88ef50990c7, 1cd23ca80784223fa2204e16203f754da4e821f8, 588706ebaf8cdb4a4161602949eba365514b1db1 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: validate STALE_COOKIE cause length before reading staleness When an ERROR chunk with a STALE_COOKIE cause is received in the COOKIE_ECHOED state, sctp_sf_do_5_2_6_stale() reads the 4-byte Measure of Staleness that follows the cause header: err = (struct sctp_errhdr *)(chunk->skb->data); stale = ntohl(*(__be32 *)((u8 *)err + sizeof(*err))); err is the first cause in the chunk, not the STALE_COOKIE cause that caused the dispatch, and nothing guarantees the staleness field is present. sctp_walk_errors() only requires a cause to be as long as the 4-byte header, so for a STALE_COOKIE cause of length 4 the read runs past the cause, and for a minimal ERROR chunk past skb->tail. The value is echoed to the peer in the Cookie Preservative of the reply INIT, leaking uninitialized memory. sctp_sf_cookie_echoed_err() already walks to the STALE_COOKIE cause, so check its length there and pass it to sctp_sf_do_5_2_6_stale(), which reads that cause instead of the first one. A STALE_COOKIE cause too short to hold the staleness field is discarded. The read is reachable by any peer that can drive an association into COOKIE_ECHOED, including an unprivileged process using a raw SCTP socket in a user and network namespace.

Published
Jul 27, 2026
Updated
Nov 3, 2026
EPSS
0.5% · 44th percentile

Report tools

JSON

Action score

36

Monitor

Low priority for now.

CVSS
36 / 40 · 9.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
9.1
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.

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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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 6022da37786701df1fc5dd946a6dcba59d5473b1affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 861f884f5471632c731cbbd612a1c072e391a624affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 588706ebaf8cdb4a4161602949eba365514b1db1affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before a257b41ddfe9e327b26581ad2777f04b23ac73f5affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 08a8f2d13f703924316e9aeac863a88ef50990c7affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before ebe0a55d954fa8da383b6192edb8f763dcb002d5affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before bbd6b2ea966cf57b6ae095cf5a8dbc993cd197a0affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 1cd23ca80784223fa2204e16203f754da4e821f8affected · 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 6.1.180-16.1.180-1
Debian:12linux-6.12before 6.12.100-1~deb12u16.12.100-1~deb12u1
Debian:13linuxbefore 6.12.100-16.12.100-1
Debian:14linuxbefore 7.1.5-17.1.5-1

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-2026-64549Jul 27, 2026 · Bluetooth: bpa10x: avoid OOB read of revision string in bpa10x_setup()
    0Monitor
  • ← EarlierCVE-2026-64550Jul 27, 2026 · net: qualcomm: rmnet: validate MAP frame length before ingress parsing
    29Monitor
  • Later →CVE-2026-64552Jul 27, 2026 · virtio-net: fix len check in receive_big()
    33Monitor

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 Linux08a8f2d13f703924316e9aeac863a88ef50990c7Vendor (CNA)
Linux Linux1cd23ca80784223fa2204e16203f754da4e821f8Vendor (CNA)
Linux Linux588706ebaf8cdb4a4161602949eba365514b1db1Vendor (CNA)
Linux Linux6022da37786701df1fc5dd946a6dcba59d5473b1Vendor (CNA)
Linux Linux861f884f5471632c731cbbd612a1c072e391a624Vendor (CNA)
Linux Linuxa257b41ddfe9e327b26581ad2777f04b23ac73f5Vendor (CNA)
Linux Linuxbbd6b2ea966cf57b6ae095cf5a8dbc993cd197a0Vendor (CNA)
Linux Linuxebe0a55d954fa8da383b6192edb8f763dcb002d5Vendor (CNA)
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).

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-6808212 days apartlibceph: fix two unsafe bare decodes in decode_lockers()
    39Monitor
  • CVE-2026-6816014 days apartceph: fix pre-auth out-of-bounds read on snaptrace in ceph_handle_caps()
    39Monitor
  • CVE-2026-6838814 days apartsmb/client: handle overlapping allocated ranges in fallocate
    39Monitor
  • CVE-2026-7208419 days apartscsi: target: Bound PR-OUT TransportID parsing to the received buffer
    39Monitor
  • CVE-2026-6834314 days apartsmb: client: validate DFS referral PathConsumed
    36Monitor
  • CVE-2026-6809814 days apartksmbd: bound DACL dedup walk to copied ACEs
    35Monitor

National notice (Türkiye Cybersecurity Directorate / USOM)

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

All national notices →

Not on record for this CVE: patch commit or PR link · researcher credit · public bounty program.

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
none
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
None
Availability impact
High

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

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

ATT&CK techniques

—

References

Show all references (7 more)

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

All records