s390/zcrypt: Fix buffer over-read in cca_cipher2protkey
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · None · High
- Fix status
- Partial Red Hat: 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: Fix buffer over-read in cca_cipher2protkey Add validation of both the actual key buffer size and token length fields in all the cca_check_sec*token() functions. Additionally check in cca_gencipherkey() for possible underflow with returned key size. The CCA token structures contain user-controlled len fields that were used in operations without proper validation against both the actual buffer size and minimum token structure size. An attacker could set this field larger than the actual buffer size, leading to reading beyond buffer boundaries. This may result in a kernel crash or exposure of memory via sending this as part of a request down to the crypto card. Also an attacker could have used a very small len value and thus enforce a buffer under-run which may produce similar effects as a over-read. So now a key must - key buf length must be at least sizeof the token struct - the key len field inside the token must fit into the range of sizeof key token struct ... key buf length
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.1.191, 6.6.160, 6.12.114, 6.18.44, 7.1.8, 7.2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
Not affected: 3 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
Timeline
- 2026-10-02 Threatist record created from CVE-2026-68453
- 2026-10-03 Alias added: GHSA-fwfm-5245-f8pj
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-20 Weakness changed · CISA ADP
- 2026-10-21 Fix available: Linux/Linux@353e442d18084b24fb3ede4e5adfca26b25f0e89, Linux/[email protected], Linux/[email protected] +1 · CNA
- 2026-10-21 2 new references · CNA
- 2026-10-30 Fix available: Linux/Linux@1adfec7be6f34c1073c9cf15040bc4e3fdc6dc51, Linux/[email protected] · CNA
- 2026-10-30 1 new reference · CNA
- 2026-11-06 Affected versions changed · Red Hat
- 2026-11-06 CVSS score changed · Red Hat
References
Other 6
- https://git.kernel.org/stable/c/1adfec7be6f34c1073c9cf15040bc4e3fdc6dc51
- https://git.kernel.org/stable/c/d0951ed366710a1a303b7cb2f8eb3d866cd68fc6
- https://git.kernel.org/stable/c/353e442d18084b24fb3ede4e5adfca26b25f0e89
- https://git.kernel.org/stable/c/a57fd7fcdb63e2d5ceac78bbe825ec986062a9da
- https://git.kernel.org/stable/c/3b2abee2a678607ae27975bc6833785c2002df43
- https://git.kernel.org/stable/c/36b230835b8a008266aad22168ca52afacc8a58d
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Sources
- CVE-2026-68453 · CVE Program
- CVE-2026-68453 · NVD
- FIRST EPSS
- GHSA-fwfm-5245-f8pj · GitHub Advisory Database · CC BY 4.0
- CVE-2026-68453 · Red Hat security data · CC BY 4.0
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