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CVE Record

CVE-2025-40019: crypto: essiv - Check ssize for decryption and in-place encryption

In the Linux kernel, the following vulnerability has been resolved: crypto: essiv - Check ssize for decryption and in-place encryption Move the ssize check to the start in essiv_aead_crypt so that it's also checked for decryption and in-place encryption.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2025-40019 is a Linux kernel crypto bug in ESSIV handling. The fix moves a size check so it also applies during decryption and in-place encryption. The public record does not provide a CVSS score, impact class, or exploitation evidence, so urgency should be driven by kernel exposure and vendor backports.

Executive priority

Treat this as a kernel maintenance item pending clearer severity data. It should enter normal patch governance, with faster handling for sensitive Linux infrastructure using kernel crypto features.

Technical view

The issue is in the Linux kernel crypto ESSIV AEAD crypt path. The resolved change checks ssize at the start of essiv_aead_crypt, covering decryption and in-place encryption cases that were previously not checked there. The bundle identifies Linux as affected and lists stable kernel commit references.

Likely exposure

Potentially exposed systems are Linux hosts running affected kernel builds where the ESSIV crypto path is present and reachable. Practical exposure cannot be confirmed from the bundle alone; validate distribution kernels and backports rather than relying only on upstream version numbers.

Exploitation context

The source bundle says this CVE is not in KEV and provides no cited evidence of active exploitation, public exploit availability, or weaponization. It also does not state whether exploitation is local, remote, or requires a specific crypto configuration.

Researcher notes

Evidence is limited to the CVE description and upstream stable commit references. No CWE, CVSS, exploit status, affected configurations, or detailed impact are provided. Avoid assuming confidentiality, integrity, availability impact until vendor analysis confirms it.

Mitigation direction

  • Apply kernel or distribution updates that include the referenced stable fixes.
  • Check Linux distribution advisories for backported CVE-2025-40019 fixes.
  • Prioritize systems using kernel cryptographic storage or ESSIV-related functionality.
  • Track vendor updates for severity, CVSS, and operational impact details.

Validation and detection

  • Inventory running kernel versions across Linux assets.
  • Confirm vendor packages include a CVE-2025-40019 fix or equivalent backport.
  • Review kernel changelogs for the referenced ESSIV ssize check change.
  • Document systems where ESSIV crypto functionality is enabled or required.
Prepared
Confidence
medium
Sources
10

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2025-40019 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
0ADP providers
9Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxbe1eb7f78aa8fbe34779c56c266ccd0364604e71, be1eb7f78aa8fbe34779c56c266ccd0364604e71, be1eb7f78aa8fbe34779c56c266ccd0364604e71, be1eb7f78aa8fbe34779c56c266ccd0364604e71, be1eb7f78aa8fbe34779c56c266ccd0364604e71, be1eb7f78aa8fbe34779c56c266ccd0364604e71, be1eb7f78aa8fbe34779c56c266ccd0364604e71, be1eb7f78aa8fbe34779c56c266ccd0364604e71unaffected
LinuxLinux5.4, 0, 5.4.301, 5.10.246, 5.15.195, 6.1.157, 6.6.113, 6.12.54, 6.17.4, 6.18affected
Weakness

CWE details

No CWE listed

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