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

CVE-2026-98531: ipv6: sr: enforce exact attribute length for SEG6_ATTR_DST

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: 0.22% (FIRST EPSS).
  • Fixed version: Linux Linux 050a0aa3c80907b8c60a396b7e04d48d8b1a9e70, 195813bb7324c338eaba0aaa02b18681ee65b670, 209eefebee54c4a5f01d68b61e8ac9881eca2de9; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.159.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 050a0aa3c80907b8c60a396b7e04d48d8b1a9e70, 195813bb7324c338eaba0aaa02b18681ee65b670, 209eefebee54c4a5f01d68b61e8ac9881eca2de9; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.159.1-1 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: ipv6: sr: enforce exact attribute length for SEG6_ATTR_DST In seg6_genl_policy, SEG6_ATTR_DST is defined with .type = NLA_BINARY and .len = sizeof(struct in6_addr). For NLA_BINARY, .len only enforces the maximum payload length and permits shorter payloads (e.g., 0 bytes). When seg6_genl_set_tunsrc() copies sizeof(struct in6_addr) bytes via kmemdup(val, sizeof(*val), GFP_KERNEL), a short SEG6_ATTR_DST attribute triggers a 16-byte out-of-bounds read past skb->tail into uninitialized skb->head memory, which is stored in sdata->tun_src and leaked back to userspace via SEG6_CMD_GET_TUNSRC. Switch SEG6_ATTR_DST in seg6_genl_policy to NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)) so that generic netlink validation rejects any attribute whose length is not exactly sizeof(struct in6_addr) with -ERANGE. Tested in QEMU against Linux 7.3.0-rc3 by sending a SEG6_CMD_SET_TUNSRC Generic Netlink message with a 0-byte SEG6_ATTR_DST attribute followed by SEG6_CMD_GET_TUNSRC. On the unfixed kernel, SEG6_CMD_SET_TUNSRC succeeds (err = 0) and SEG6_CMD_GET_TUNSRC leaks 16 bytes of uninitialized kernel heap memory (tun_src = 836a61ecc4d25a1042a8d60411cfb378); with this patch applied, SEG6_CMD_SET_TUNSRC is rejected by netlink policy validation with -ERANGE (-34) and tun_src remains zeroed.

—No exploit Fix available
Published
Oct 18, 2026
Updated
Oct 19, 2026
EPSS
0.2% · 12th 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 · 0.2%

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Noroxi analysis

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Affected systems

Is your version affected?

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—

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

    • 4.10affected
    • 915d7e5e5930b4f01d0971d93b9b25ed17d221aa and later · before 050a0aa3c80907b8c60a396b7e04d48d8b1a9e70affected · git
    • 915d7e5e5930b4f01d0971d93b9b25ed17d221aa and later · before 209eefebee54c4a5f01d68b61e8ac9881eca2de9affected · git
    • 915d7e5e5930b4f01d0971d93b9b25ed17d221aa and later · before e3ac68c1cdc2535d127b2bfd50c263d16c8e4199affected · git
    • 915d7e5e5930b4f01d0971d93b9b25ed17d221aa and later · before 66bf65fa109326e4c4ddeb0b94093379f72838fdaffected · git
    • 915d7e5e5930b4f01d0971d93b9b25ed17d221aa and later · before 195813bb7324c338eaba0aaa02b18681ee65b670affected · git
    • 915d7e5e5930b4f01d0971d93b9b25ed17d221aa and later · before 6fcfc362344edea745a69f3a705de50b731f3418affected · git
    • 915d7e5e5930b4f01d0971d93b9b25ed17d221aa and later · before 94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0eaffected · git
    • 915d7e5e5930b4f01d0971d93b9b25ed17d221aa and later · before 2d959c75c27f90e9ec489d18ce5ee6b852ad4741affected · git
    • before 4.10not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.190-16.1.190-1
Debian:12linux-6.12before 6.12.113-1~deb12u16.12.113-1~deb12u1
Debian:13linuxbefore 6.12.113-16.12.113-1
Debian:14linuxbefore 7.2.9-17.2.9-1

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-2026-98529Oct 18, 2026 · gpio: arizona: Fix runtime PM leak in arizona_gpio_direction_out()
    0Monitor
  • ← EarlierCVE-2026-98530Oct 18, 2026 · kprobes: Fix permanent hang when flushing the kprobe optimizer
    0Monitor
  • Later →CVE-2026-98532Oct 18, 2026 · ipv6: do not let ipv6_find_hdr() return an offset past the packet end
    32Monitor

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 Linux050a0aa3c80907b8c60a396b7e04d48d8b1a9e70Vendor (CNA)
Linux Linux195813bb7324c338eaba0aaa02b18681ee65b670Vendor (CNA)
Linux Linux209eefebee54c4a5f01d68b61e8ac9881eca2de9Vendor (CNA)
Linux Linux2d959c75c27f90e9ec489d18ce5ee6b852ad4741Vendor (CNA)
Linux Linux66bf65fa109326e4c4ddeb0b94093379f72838fdVendor (CNA)
Linux Linux6fcfc362344edea745a69f3a705de50b731f3418Vendor (CNA)
Linux Linux94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0eVendor (CNA)
Linux Linuxe3ac68c1cdc2535d127b2bfd50c263d16c8e4199Vendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.06.6.159.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.1.190-1 · Debian:12Package registry (OSV)
debian:linux-6.126.12.113-1~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.

  1. Published
  2. Fix recordedsame day
  3. TodayOct 31, 2026+12 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✗ → ✓

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References

Show all references (7 more)

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

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