Security readout for executives and security teams
Plain-English summary
A local, low-privileged user may trigger unsafe Linux kernel handling of shared packet-memory fragments in RxRPC. Successful exploitation could corrupt protected memory and affect confidentiality, integrity, and availability. This is high severity, but the supplied evidence does not show remote exploitation or confirmed attacks in the wild.
Executive priority
Prioritize prompt assessment and patching, especially on shared or multi-tenant Linux systems. This is not presented as an internet-remote vulnerability, but local low-privileged access may be enough. Escalate systems combining untrusted users, affected kernels, and RxRPC use; track vendor determinations where version status remains unclear.
Technical view
RxRPC DATA and RESPONSE processing could decrypt in place when an skb was not cloned but still referenced externally owned paged fragments. Those pages were placed directly into the cryptographic scatter-gather list, permitting writes into shared memory. The fix also unshares packets with fragment lists or shared fragments before security operations.
Likely exposure
Exposure requires an affected Linux kernel, local low-privileged access, and a reachable RxRPC processing path involving shared or chained paged fragments. The supplied affected-version data is ambiguous, so kernel builds and distribution advisories must be checked individually. The CVSS vector rates this as local, low complexity, low privileges, and no user interaction.
Exploitation context
A public repository is referenced and tagged as an exploit, indicating technical reproduction material may exist. However, the source bundle reports no CISA KEV listing and provides no evidence of active exploitation. Treat exploit maturity as uncertain rather than assuming attacks are occurring.
Researcher notes
The vulnerable gate relied only on skb_cloned(). Shared fragments introduced through splice-related UDP handling or chained fragment lists could therefore reach in-place cryptographic processing. Stable fixes extend the copy/unshare condition to skb_has_frag_list() and skb_has_shared_frag(), while retaining zero-copy handling for kernel-private fragments. The bundle does not establish exploit reliability or affected distribution packages.
Mitigation direction
- Install the distribution or vendor kernel update containing the applicable stable fix.
- Check Linux and distribution advisories for exact affected and corrected kernel builds.
- Prioritize multi-user systems where untrusted users can obtain local access.
- Restrict unnecessary local accounts and workloads until affected systems are updated.
Validation and detection
- Inventory running kernel builds across Linux systems.
- Compare each build against vendor advisories and the cited stable fixes.
- Confirm updated systems booted into the corrected kernel, not an older installed build.
- Review whether exposed systems use RxRPC and permit untrusted local access.
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.
CWE-123: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-787: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-43500 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
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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.
SSVC decision data
CVSS vector scores
3 official scoresWe 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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9redhat-SADPVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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.
- ADP timelineredhat-SADP
Reported to Red Hat.
- ADP timelineredhat-SADP
Made public.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2026-05-11T00:00:00.000Z: Reported to Red Hat.
- 2026-05-11T00:00:00.000Z: Made public.
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/7c504ffab3efce8f7e4f463b314ae31030bdf18bCVE reference, Linux
- https://git.kernel.org/stable/c/3711382a77342a9a1c3d2e7330dcfc7ea927f568CVE reference, Linux
- https://git.kernel.org/stable/c/3eae0f4f9f7206a4801efa5e0235c25bbd5a412cCVE reference, Linux
- https://git.kernel.org/stable/c/d45179f8795222ce858770dc619abe51f9d24411CVE reference, Linux
- https://git.kernel.org/stable/c/aa54b1d27fe0c2b78e664a34fd0fdf7cd1960d71CVE reference, Linux
- https://github.com/V4bel/dirtyfragCVE reference, CISA-ADP · exploit
- https://access.redhat.com/security/cve/CVE-2026-43500CVE reference, redhat-SADP · vdb-entry, x_refsource_REDHAT
- RHBZ#2468273CVE reference, redhat-SADP · issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43500.jsonCVE reference, redhat-SADP · x_sadp-csaf-vex
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.
Write-what-where Condition
Write-what-where Condition represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Out-of-bounds Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.