EchelonGraph verdictMonitorNo release containing the referenced fix is confirmed: check the referenced fix and the vendor's advisory for a release that contains it; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule (the SSVC decision on this page).
- •Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.8Exploit: None knownExposed services: Not assessed
A fix is referenced (a reference tagged "Patch", often a source commit), but no release containing it is confirmed — find the release that contains it; until it is applied, mitigate (WAF / firewall / segmentation).
The CC1200 sub-GHz IEEE 802.15.4 driver takes the PHY packet length from the first byte of the radio's RX FIFO in get_packet_length() and validates it in verify_rxfifo_validity() (drivers/ieee802154/ieee802154_cc1200.c). That validation only enforced a lower bound (pkt_len < 3); its second clause rejects a FIFO that holds more bytes than declared and therefore never bounds large values. Because the driver configures the radio for variable packet length with PKT_LEN = 0xFF, the length byte is an over-the-air value of 0-255 that reached net_pkt_rx_alloc_with_buffer() and the subsequent SPI burst read unclamped.
An unauthenticated attacker within radio range can transmit a frame that presents a length byte above the IEEE 802.15.4 maximum of 127 while the chip's 128-byte RX FIFO has not overflowed, so the driver's RX_FIFO_ERROR pre-check does not fire. Reaching this state depends on RF framing and timing, since the RX thread is driven off the PKT_SYNC_RXTX signal and may sample the FIFO before a packet is complete; no pairing, authentication, or user interaction is required.
With the default CONFIG_NET_BUF_FIXED_DATA_SIZE and CONFIG_NET_BUF_DATA_SIZE=128, an allocation larger than one fragment is satisfied by a chain of fragments, but read_rxfifo_content() performs a single SPI burst of pkt_len bytes into the first fragment's buf->data and then calls net_buf_add() with the same length. A length above 128 therefore writes up to 127 bytes past the end of a fragment in the contiguous rx_bufs pool and leaves a net_buf whose len exceeds its capacity. The overflowing bytes are FIFO-underflow output rather than attacker-chosen data, so the practical impact is network-buffer-pool corruption and crashes rather than a controlled write. Only builds that enable CONFIG_IEEE802154_CC1200 with an attached CC1200 radio are affected.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (6.8): severity, escalated by confirmed exploitation. This CVE's 6.8 is its impact severity (EG Severity), not escalated.
- EG Severity
- 6.8 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
- EG Likelihood
- 0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it