ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2026-43500

Linux Kernel Out-of-bounds Write

Published May 11, 2026 · catalog updated Aug 24, 2026 · Linux Kernel

Patch now

CVE-2026-43500 is in the CISA known-exploited catalog. Confirm Linux Kernel against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Severity
High7.8
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
2.26%
Remediation
Remediation guidance
Affected products
cpe linux/linux kernel · vendor Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Also unshare DATA/RESPONSE packets when paged frags are present The DATA-packet handler in rxrpc_input_call_event() and the RESPONSE handler in rxrpc_verify_response() copy the skb to a linear one before calling into the security ops only when skb_cloned() is true. An skb that is not cloned but still carries externally-owned paged fragments (e.g. SKBFL_SHARED_FRAG set by splice() into a UDP socket via __ip_append_data, or a chained skb_has_frag_list()) falls through to the in-place decryption path, which binds the frag pages directly into the AEAD/skcipher SGL via skb_to_sgvec(). Extend the gate to also unshare when skb_has_frag_list() or skb_has_shared_frag() is true. This catches the splice-loopback vector and other externally-shared frag sources while preserving the zero-copy fast path for skbs whose frags are kernel-private (e.g. NIC page_pool RX, GRO). The OOM/trace handling already in place is reused.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe linux/linux kernel5.3
  • cpe linux/linux kernel7.1
  • vendor Linux Kernelversion unspecified

How to fix CVE-2026-43500

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2026-43500 is in the CISA known-exploited catalog. Confirm Linux Kernel against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Compare what you have installed with linux/linux kernel 5.3; linux/linux kernel 7.1. Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

What should an analyst verify?

CWE-123; CWE-787: Out-of-bounds Write. EPSS 2.26%. The CISA KEV listing is the exploitation evidence. A public exploit reference is linked in Sources. That is not the same as confirmed exploitation. Use the source links for the original advisory.

Technology hubs

Fortinet security

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. May 11, 2026 · CISA KEV

    Known exploited

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

  2. May 11, 2026 · NIST NVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: rxrpc: Also unshare DATA/RESPONSE packets when paged frags are present The DATA-packet handler in rxrpc_input_call_event() and the RESPONSE handler in rxrpc_verify_response() copy the skb to a linear one before calling into the security ops only when skb_cloned() is true. An skb that is not cloned but still carries externally-owne

  3. Aug 24, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: rxrpc: Also unshare DATA/RESPONSE packets when paged frags are present The DATA-packet handler in rxrpc_input_call_event() and the RESPONSE handler in rxrpc_verify_response() copy the skb to a linear one before calling into the security ops only when skb_cloned() is true. An skb that is not cloned but still carries externally-owne

Sources

  • CVE.orgVulnerability recordCVE-2026-43500

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-43500

    30-day exploitation probability 2.3%

    first.org
  • Fortinet PSIRTVendor advisoryCVE-2026-43500

    CVSSv3 Score: 8.8 Linux kernel is impacted by CVE-2026-43284 and CVE-2026-43500 which chained together create the Dirty Frag vulnerability.CVE-2026-43284In the Linux kernel, the following vulnerability has been resolved: xfrm: esp: avoid in-place decrypt on shared skb frags MSG_S

    fortiguard.fortinet.com
  • Metasploit ModulesPublic exploit moduleexploit_linux/local/cve_2026_43500_dirty_frag

    Public module reference (good). Module source is not copied into this catalog.

    rapid7.com
  • NIST NVDVulnerability recordCVE-2026-43500

    In the Linux kernel, the following vulnerability has been resolved: rxrpc: Also unshare DATA/RESPONSE packets when paged frags are present The DATA-packet handler in rxrpc_input_call_event() and the RESPONSE handler in rxrpc_verify_response() copy the skb to a linear one before

    nvd.nist.gov
  • VulnCheck KEVConfirmed exploitationCVE-2026-43500

    In the Linux kernel, the following vulnerability has been resolved: rxrpc: Also unshare DATA/RESPONSE packets when paged frags are present The DATA-packet handler in rxrpc_input_call_event() and the RESPONSE handler in rxrpc_verify_response() copy the skb to a linear one before c

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.