Security readout for executives and security teams
Plain-English summary
A Linux IPv6 IOAM processing flaw can dereference missing kernel data and crash an affected system. The supplied CVSS assessment treats it as remotely reachable without authentication or user interaction, affecting availability rather than data confidentiality or integrity.
Executive priority
Prioritize prompt assessment and patching on availability-sensitive, network-facing Linux infrastructure. The possible outcome is system disruption rather than data theft, and active exploitation is not established. Avoid declaring fleet exposure solely from upstream version numbers because distributor backports may change status.
Technical view
The flaw is in __ioam6_fill_trace_data(). __in6_dev_get() may return NULL, leading to a kernel NULL dereference. The fixes add a NULL check, replace skb_dst_dev() with skb_dst_dev_rcu(), and add two READ_ONCE() operations. The CVSS score is 7.5.
Likely exposure
Exposure is most likely on Linux systems where IPv6 IOAM reaches the vulnerable trace-data path. The bundle lists affected versions including 5.15, 6.18.24, 6.19.14, and 7.0, but does not provide clear range or distribution-package mappings. Confirm status with each Linux distributor.
Exploitation context
The supplied record is not in KEV, and no cited source establishes active exploitation or a public exploit. CVSS rates the issue network-accessible, low complexity, unauthenticated, and capable of causing high availability impact. Treat that as severity assessment, not proof of practical exploitation.
Researcher notes
The source bundle provides no CWE and has ambiguous affected-version data, including duplicated hashes and an unexplained version entry. Three stable-kernel fixes are referenced, but their exact branch mappings are not supplied. Validate reachability, configuration, and backports before concluding exploitability or exposure.
Mitigation direction
- Apply a vendor kernel update containing the applicable linked stable fix.
- Consult your Linux distributor for affected package ranges and backport status.
- If updates are delayed, follow vendor guidance for temporary mitigations; none are documented here.
- Prioritize systems using IPv6 IOAM or receiving untrusted IPv6 traffic.
Validation and detection
- Inventory deployed Linux kernel versions and distribution package revisions.
- Compare each revision against distributor advisories for CVE-2026-43101.
- Verify packages include an applicable linked fix or documented backport.
- Determine whether IPv6 IOAM functionality is enabled or operationally used.
- Review kernel telemetry for crashes involving __ioam6_fill_trace_data().
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2026-43101 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6LinuxVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/4198aab6f000b4febb18ea820fea20634dd789c7CVE reference, Linux
- https://git.kernel.org/stable/c/3719c234fa94c37c955b1ecd3742ef280ec135e6CVE reference, Linux
- https://git.kernel.org/stable/c/4e65a8b8daa18d63255ec58964dd192c7fdd9f8bCVE reference, Linux
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.