Evidence used
- No CISA KEV confirmation is currently recorded.
- Exploitation requires an existing local or physical foothold with privileges.
- EPSS is 0.11% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-17051High confidence
Out-of-bounds write in the Intel SEDI IPM driver from an unvalidated inbound doorbell length
zephyrproject · zephyr
6.0MediumCVSS 3.1
Scheduled
Patch availableMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Low, lowered one band.downgradedsince 21 Sep 2026
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict local access and enforce least privilege on affected hosts.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs zephyrproject zephyr and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Patch available01
What, why and how
The Intel SEDI IPM (inter-processor mailbox) driver in drivers/ipm/ipm_sedi.c handles an inbound message interrupt in ipm_event_dispose(). It read the peer-written doorbell register, extracted the payload length with IPC_HEADER_GET_LENGTH(), and passed that length straight to sedi_ipc_read_msg() to copy the message into struct ipm_sedi_context.incoming_data_buf, without checking it against the buffer size. The doorbell length field is 10 bits wide (IPC_HEADER_LENGTH_MASK is 0x03FF), so it can encode up to 1023 bytes, while incoming_data_buf is IPC_DATA_LEN_MAX (128) bytes. The bounds check in the underlying HAL sedi_ipc_read_msg() is a DBG_CHECK that compiles away unless CONFIG_DEBUG is set, so no check remained in a production image. The doorbell register is written by the peer processor on the other side of the IPC link — for the intel_ish_5_* targets, the host CPU's ISH driver, reached through the device's memory-mapped register window. Host-side software with driver-level or raw BAR access can therefore set a length of up to 1023 and cause the interrupt handler to copy far past the destination buffer. The affected path requires an application to have registered an IPM receive callback via ipm_register_callback(), which is the driver's normal mode of use. The result is an out-of-bounds write of up to 895 bytes into static (.bss) memory, performed in interrupt context. The overflow first clobbers the rest of struct ipm_sedi_context — including the k_sem and k_mutex used by the transmit path, whose wait queues contain self-referential list pointers — and then adjacent static data, giving a kernel data-structure corruption and crash primitive. The overflowing bytes are read from registers following the message window, a portion of which are themselves peer-programmable. The fix rejects any doorbell whose encoded length exceeds IPC_DATA_LEN_MAX, logging it and acknowledging the doorbell so the peer is not left waiting.
What
The Intel SEDI IPM (inter-processor mailbox) driver in drivers/ipm/ipm_sedi.c handles an inbound message interrupt in ipm_event_dispose(). It read the peer-written doorbell register, extracted the payload length with IPC_HEADER_GET_LENGTH(), and passed that length straight to sedi_ipc_read_msg() to copy the message into struct ipm_sedi_context.incoming_data_buf, without checking it against the buffer size. The doorbell length field is 10 bits wide (IPC_HEADER_LENGTH_MASK is 0x03FF), so it can encode up to 1023 bytes, while incoming_data_buf is IPC_DATA_LEN_MAX (128) bytes. The bounds check in the underlying HAL sedi_ipc_read_msg() is a DBG_CHECK that compiles away unless CONFIG_DEBUG is set, so no check remained in a production image. The doorbell register is written by the peer processor on the other side of the IPC link — for the intel_ish_5_* targets, the host CPU's ISH driver, reached through the device's memory-mapped register window. Host-side software with driver-level or raw BAR access can therefore set a length of up to 1023 and cause the interrupt handler to copy far past the destination buffer. The affected path requires an application to have registered an IPM receive callback via ipm_register_callback(), which is the driver's normal mode of use. The result is an out-of-bounds write of up to 895 bytes into static (.bss) memory, performed in interrupt context. The overflow first clobbers the rest of struct ipm_sedi_context — including the k_sem and k_mutex used by the transmit path, whose wait queues contain self-referential list pointers — and then adjacent static data, giving a kernel data-structure corruption and crash primitive. The overflowing bytes are read from registers following the message window, a portion of which are themselves peer-programmable. The fix rejects any doorbell whose encoded length exceeds IPC_DATA_LEN_MAX, logging it and acknowledging the doorbell so the peer is not left waiting.
Why
A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.
How
An attacker operating through local access may attempt exploitation with elevated privileges. If successful, the issue may disrupt the affected service.
What
The Intel SEDI IPM (inter-processor mailbox) driver in drivers/ipm/ipm_sedi.c handles an inbound message interrupt in ipm_event_dispose(). It read the peer-written doorbell register, extracted the payload length with IPC_HEADER_GET_LENGTH(), and passed that length straight to sedi_ipc_read_msg() to copy the message into struct ipm_sedi_context.incoming_data_buf, without checking it against the buffer size. The doorbell length field is 10 bits wide (IPC_HEADER_LENGTH_MASK is 0x03FF), so it can encode up to 1023 bytes, while incoming_data_buf is IPC_DATA_LEN_MAX (128) bytes. The bounds check in the underlying HAL sedi_ipc_read_msg() is a DBG_CHECK that compiles away unless CONFIG_DEBUG is set, so no check remained in a production image. The doorbell register is written by the peer processor on the other side of the IPC link — for the intel_ish_5_* targets, the host CPU's ISH driver, reached through the device's memory-mapped register window. Host-side software with driver-level or raw BAR access can therefore set a length of up to 1023 and cause the interrupt handler to copy far past the destination buffer. The affected path requires an application to have registered an IPM receive callback via ipm_register_callback(), which is the driver's normal mode of use. The result is an out-of-bounds write of up to 895 bytes into static (.bss) memory, performed in interrupt context. The overflow first clobbers the rest of struct ipm_sedi_context — including the k_sem and k_mutex used by the transmit path, whose wait queues contain self-referential list pointers — and then adjacent static data, giving a kernel data-structure corruption and crash primitive. The overflowing bytes are read from registers following the message window, a portion of which are themselves peer-programmable. The fix rejects any doorbell whose encoded length exceeds IPC_DATA_LEN_MAX, logging it and acknowledging the doorbell so the peer is not left waiting.
Why
A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.
How
An attacker operating through local access may attempt exploitation with elevated privileges. If successful, the issue may disrupt the affected service.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- local access → Out-of-bounds Write → disrupt the affected service
- Attack surface
- Local
- Privileges required
- High: elevated access is required
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-787 ↗
CWE-787: Out-of-bounds Write. The product writes data past the end, or before the beginning, of the intended buffer.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Affected
- zephyr: 3.5.0 < 4.4.2
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 21 Sept 2026 · Last source change 21 Sept 2026, 18:48 UTC · CWE-787 · Out-of-bounds Write
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-09-22
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-84013
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD awaiting enrichment
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- ENISA EUVD mappingEUVD-2026-84013 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-84013"}
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.