In the Linux kernel, the following vulnerability has been resolved:
spi: spi-qpic-snand: write the feature value before executing SET_FEATURE
qcom_spi_send_cmdaddr() programs NAND_FLASH_CMD/NAND_EXEC_CMD and submits
the descriptors, which makes the controller execute the command
immediately. For SPINAND_SET_FEATURE the value to be written is only
placed into NAND_FLASH_FEATURES afterwards, by qcom_spi_io_op(), in a
second submission - so the chip is programmed with whatever that register
happened to hold from a previous operation, and the intended value is only
applied by the *next* SET_FEATURE.
Measured on a TP-Link Archer AX55 v1 (IPQ5018, ESMT F50L1G41LB): writing
0x40 to the configuration register (0xb0) leaves the chip at 0x00, and the
subsequent write of 0x00 leaves it at 0x40 - every write lands one
operation late.
This stayed unnoticed until v6.18 added SPI-NAND OTP support together
with OTP entries for ESMT chips. spinand_otp_rw() enables OTP mode,
reads, and disables it again, and mtd_otp_nvmem_add() does this during
MTD registration. With the off-by-one, the "disable" write actually
applies the previously requested value, so CFG_OTP_ENABLE ends up set:
the chip stays in OTP mode, every subsequent array read returns the OTP
area instead of the array (UBI reports an empty device) and all writes
fail with -EIO because the OTP area is write protected. On this board
that makes the whole flash unusable and the device unbootable.
Write the feature value into NAND_FLASH_FEATURES as part of the same
transaction, before NAND_EXEC_CMD. While at it, copy only the bytes the
operation actually carries - the previous code dereferenced a 4-byte
pointer on a one-byte buffer (spinand->scratchbuf).
With this patch the flash contents read back bit-identical to a
known-good dump of the same board taken under the vendor firmware
(md5-verified across partitions), and writes work.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (8.4): severity, escalated by confirmed exploitation. This CVE's 8.4 is its impact severity (EG Severity), not escalated.
- EG Severity
- 8.4 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-27). 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 low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” 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