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Vulnerabilities

Vulnerability · CVE-2026-82390

Cross-session AES key confusion in the Espressif ESP32 hardware crypto driver

Published Oct 26, 2026 · catalog updated Nov 4, 2026 · Cross-session AES key confusion

Last checked Nov 5, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-82390. EPSS is 0.20%. Act only if a listed version of Cross-session AES key confusion is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Cross-session AES key confusion).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Low3.7
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.20%
Remediation
Advisory link
Affected products
vendor zephyrproject zephyr

The Espressif AES driver drivers/crypto/crypto_esp32_aes.c advertises a multi-session cipher API — it hands out up to CONFIG_ESP32_CRYPTO_AES_SESSIONS_MAX (default 4) independent sessions, each carrying its own key and direction. The AES peripheral, however, has a single chip-global set of key and mode registers, and aes_begin_session() programmed them exactly once, at session start, outside the aes_lock mutex that serialises the transforms. The per-operation handlers aes_ecb_op(), aes_cbc_op() and aes_ctr_op() then ran aes_hal_transform_block() against whatever key and direction the registers happened to hold. As a result, once a second session is opened with a different key, every subsequent operation on the first session silently uses the second session's key and direction, and no error is reported. Because the key programming happened outside the lock, the correct usage pattern of "each thread does begin, then op, then free on its own session" also races: a second thread's cipher_begin_session() landing between the first thread's begin and its operation makes that operation run under the second thread's key. An attacker who can induce session creation on the device — for example a protocol peer whose connection causes a session key to be installed — can influence which key is resident when a victim operation runs. The impact is a cryptographic failure rather than memory corruption: data the application believed it was protecting under one key is encrypted or decrypted under another. Where the resident key is one the attacker knows or supplied, the affected plaintext becomes recoverable by that attacker, and the operation's direction (encrypt versus decrypt) can likewise be inverted. Exposure requires an application that holds two or more concurrent sessions with different keys against this driver; no in-tree Zephyr subsystem does so today (the 802.15.4 security layer, which does open two sessions, uses CCM mode, which this driver rejects), so the risk falls on a

Are you affected?

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

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  • vendor zephyrproject zephyrversion unspecified

How to fix CVE-2026-82390

  • No stored fix

    No vendor fix text is stored. Use the linked advisory before you change production.

  • Version check

    No version range is stored, so an installed version cannot be checked on this page.

  • Advisory

    Open the cve_org record and follow its fix.

  • Official advisories

What to do

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

Should you patch?

No confirmed exploitation is on record for CVE-2026-82390. EPSS is 0.20%. Act only if a listed version of Cross-session AES key confusion is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-362: Race Condition. EPSS 0.20%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

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

Timeline

Detection, updates, and resolution for this record.

  1. Nov 4, 2026 · Tenable CVE Database

    Detected

    The Espressif AES driver drivers/crypto/crypto_esp32_aes.c advertises a multi-session cipher API — it hands out up to CONFIG_ESP32_CRYPTO_AES_SESSIONS_MAX (default 4) independent sessions, each carrying its own key and direction. The AES peripheral, however, has a single chip-global set of key and mode registers, and aes_begin_session() programmed them exactly once, at session start, outside the a

  2. Nov 4, 2026 · CVE.org

    Updated

    The Espressif AES driver drivers/crypto/crypto_esp32_aes.c advertises a multi-session cipher API — it hands out up to CONFIG_ESP32_CRYPTO_AES_SESSIONS_MAX (default 4) independent sessions, each carrying its own key and direction. The AES peripheral, however, has a single chip-global set of key and mode registers, and aes_begin_session() programmed them exactly once, at session start, outside the a

Sources

  • CVE.orgVulnerability recordCVE-2026-82390

    The Espressif AES driver drivers/crypto/crypto_esp32_aes.c advertises a multi-session cipher API — it hands out up to CONFIG_ESP32_CRYPTO_AES_SESSIONS_MAX (default 4) independent sessions, each carrying its own key and direction. The AES peripheral, however, has a single chip-glo

    cve.org
  • Tenable CVE DatabaseVulnerability recordCVE-2026-82390

    The Espressif AES driver drivers/crypto/crypto_esp32_aes.c advertises a multi-session cipher API — it hands out up to CONFIG_ESP32_CRYPTO_AES_SESSIONS_MAX (default 4) independent sessions, each carrying its own key and direction. The AES peripheral, however, has a single chip-global set of key and mode registers, and aes_begin_session() programmed them exactly once, at session start, outside the a

    tenable.com

References

Freshness

Last verified in this catalog Nov 4, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • CVE.orgNov 5, 2026
  • Tenable CVE DatabaseNov 4, 2026