CVE-2026-93287

HIGHPre-NVD 7.87.8—
EchelonGraph scoreHIGH confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-09-24. A secondary CVSS source baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
7.8EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 7.8Exploit: None knownExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

In the Linux kernel, the following vulnerability has been resolved:

i2c: smbus: reject oversized block transfers in the common path

The SMBus block transfer length data->block[0] is validated in i2c_smbus_xfer_emulated() but that check runs too late for tracepoints and is skipped entirely when the adapter provides a native smbus_xfer implementation. This allows user-controlled oversized block lengths to reach tracepoint memcpy calls and driver callbacks unchecked.

Add an early validation in __i2c_smbus_xfer() that rejects block transfers whose caller-supplied length is zero or exceeds I2C_SMBUS_BLOCK_MAX before any tracepoint fires or driver callback runs. data->block[0] is filled in by the device on SMBus block reads, so the check is scoped to operations where the length is actually supplied by the caller. This is consistent with the existing -EINVAL convention in the emulated path and protects all downstream consumers at once: the smbus_write tracepoint, all native smbus_xfer driver implementations, and the emulated path.

Two distinct bugs are fixed by this change:

Bug 1: smbus_write tracepoint OOB (include/trace/events/smbus.h) trace_smbus_write() fires before any validation and copies data->block[0]+1 bytes into a 34-byte event buffer. With block[0]=0xfe the tracepoint copies 255 bytes, overflowing by 221.

BUG: KASAN: stack-out-of-bounds in trace_event_raw_event_smbus_write+0x27c/0x530 Read of size 255 at addr ffff88800d98fcf8 by task poc_smbus/91 Call Trace: __asan_memcpy+0x23/0x80 trace_event_raw_event_smbus_write+0x27c/0x530 __i2c_smbus_xfer+0x43a/0xa40 i2c_smbus_xfer+0x19e/0x340 i2cdev_ioctl_smbus+0x38f/0x7f0 i2cdev_ioctl+0x35e/0x680 __x64_sys_ioctl+0x147/0x1e0 do_syscall_64+0xcf/0x15a0 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Bug 2: i2c-stub I2C_SMBUS_I2C_BLOCK_DATA OOB (drivers/i2c/i2c-stub.c) stub_xfer() implements .smbus_xfer directly and only clamps block[0] against 256-command, not I2C_SMBUS_BLOCK_MAX. With block[0]=0xff and command=0 the loop accesses block[1+i] for i up to 254, far past the 34-byte union.

UBSAN: array-index-out-of-bounds in drivers/i2c/i2c-stub.c:223:44 index 34 is out of range for type '__u8 [34]' Call Trace: __ubsan_handle_out_of_bounds+0xd7/0x120 stub_xfer+0x1971/0x198f [i2c_stub] __i2c_smbus_xfer+0x306/0xa40 i2c_smbus_xfer+0x19e/0x340 i2cdev_ioctl_smbus+0x38f/0x7f0 i2cdev_ioctl+0x35e/0x680 __x64_sys_ioctl+0x147/0x1e0 do_syscall_64+0xcf/0x15a0 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Both traces reproduced on v7.0-rc6+i2c/for-current with KASAN+UBSAN.

CVSS v3
7.8
EG Score
7.8HIGHhigh confidence
EG Risk
40
EG Risk 40/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity78% × 45%
Exploitation0% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
0.1%
EPSS %ILE
2nd
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 24, 2026

Last Modified

October 3, 2026

Advisory Details (3)

Auto-updated Sep 25, 2026
No patch confirmed yet.
generic

i2c: smbus: reject oversized block transfers in the common path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f09edffba97d37b1fdff5f818a9a45f8a98ac171
generic

i2c: smbus: reject oversized block transfers in the common path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c4b478bc50b7ca9865e237909941253a0f7111a2
generic

i2c: smbus: reject oversized block transfers in the common path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/3051cd060fa496df42954291fa2306ed2eab4ecc

Vendor Advisories for CVE-2026-93287(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(4 across 3 ecosystems)
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 7.2~rc7-1~exp1 (360 versions)
  • every version on: no fix on record
—
linux-6.126.12.100-1~deb12u1, 6.12.101-1~deb12u1, 6.12.107-1~deb12u1
  • every version up to 6.12.111-1~deb12u1: fixed in 6.12.111-1~deb12u1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 6.12.96-1 (35 versions)
  • every version up to 6.12.111-1: fixed in 6.12.111-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.1~rc7-1~exp1 (157 versions)
  • every version up to 7.1.3-1: fixed in 7.1.3-1
—

Data Freshness Timeline

(refreshed 38× in last 7d / 57× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-05 02:10 UTCEG score recompute
  2. 2026-10-05 02:10 UTCVendor advisory
  3. 2026-10-05 02:10 UTCGHSA enrichment
  4. 2026-10-04 23:23 UTCEPSS rescore
  5. 2026-10-04 13:16 UTCVendor advisory
  6. 2026-10-04 13:16 UTCGHSA enrichment
  7. 2026-10-04 00:24 UTCEG score recompute
  8. 2026-10-04 00:24 UTCVendor advisory
  9. 2026-10-04 00:24 UTCGHSA enrichment
  10. 2026-10-03 11:33 UTCVendor advisory
  11. 2026-10-03 11:33 UTCGHSA enrichment
  12. 2026-10-03 06:27 UTCEG score recompute
  13. 2026-10-03 06:27 UTCVendor advisory
  14. 2026-10-03 06:27 UTCGHSA enrichment
  15. 2026-10-02 17:35 UTCVendor advisory
  16. 2026-10-02 17:35 UTCGHSA enrichment
  17. 2026-10-02 04:44 UTCEG score recompute
  18. 2026-10-02 04:43 UTCVendor advisory
  19. 2026-10-02 04:43 UTCGHSA enrichment
  20. 2026-10-01 19:51 UTCEPSS rescore
  21. 2026-10-01 15:52 UTCVendor advisory
  22. 2026-10-01 15:52 UTCGHSA enrichment
  23. 2026-10-01 03:00 UTCEG score recompute
  24. 2026-10-01 03:00 UTCVendor advisory
  25. 2026-10-01 03:00 UTCGHSA enrichment
Show 32 more
  1. 2026-09-30 15:04 UTCEPSS rescore
  2. 2026-09-30 14:07 UTCVendor advisory
  3. 2026-09-30 14:07 UTCGHSA enrichment
  4. 2026-09-30 01:16 UTCEG score recompute
  5. 2026-09-30 01:16 UTCVendor advisory
  6. 2026-09-30 01:16 UTCGHSA enrichment
  7. 2026-09-29 12:24 UTCVendor advisory
  8. 2026-09-29 12:24 UTCGHSA enrichment
  9. 2026-09-28 23:32 UTCEG score recompute
  10. 2026-09-28 23:32 UTCVendor advisory
  11. 2026-09-28 23:32 UTCGHSA enrichment
  12. 2026-09-28 13:52 UTCEPSS rescore
  13. 2026-09-28 13:52 UTCEPSS rescore
  14. 2026-09-28 10:40 UTCVendor advisory
  15. 2026-09-28 10:40 UTCGHSA enrichment
  16. 2026-09-27 21:48 UTCEG score recompute
  17. 2026-09-27 21:48 UTCGHSA enrichment
  18. 2026-09-27 13:49 UTCEPSS rescore
  19. 2026-09-27 08:54 UTCGHSA enrichment
  20. 2026-09-26 20:03 UTCEG score recompute
  21. 2026-09-26 20:03 UTCGHSA enrichment
  22. 2026-09-26 15:59 UTCEPSS rescore
  23. 2026-09-26 07:09 UTCEG score recompute
  24. 2026-09-26 07:09 UTCGHSA enrichment
  25. 2026-09-25 18:17 UTCEG score recompute
  26. 2026-09-25 18:17 UTCGHSA enrichment
  27. 2026-09-25 05:18 UTCEG score recompute▲ 7.80
  28. 2026-09-25 05:18 UTCGHSA enrichment
  29. 2026-09-25 05:16 UTCMITRE cvelistV5CVSS v3 → 7.8 · severity → HIGH
  30. 2026-09-24 17:33 UTCNVD update
  31. 2026-09-24 16:31 UTCEG score recompute
  32. 2026-09-24 16:26 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-93287?
CVE-2026-93287 is a high vulnerability published on September 24, 2026. In the Linux kernel, the following vulnerability has been resolved: i2c: smbus: reject oversized block transfers in the common path The SMBus block transfer length data->block[0] is validated in i2csmbusxfer_emulated() but that check runs too late for tracepoints and is skipped entirely when the…
When was CVE-2026-93287 disclosed?
CVE-2026-93287 was first published on September 24, 2026, with the most recent update on October 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-93287 actively exploited?
CVE-2026-93287 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (2nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-93287?
CVE-2026-93287 has a CVSS base score of 7.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-93287?
No fix for CVE-2026-93287 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-93287 are linked in the Vendor Advisories panel on this page.

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