VulnTideExploited vulnerabilities, by vendor. Data as of .
Not in CISA KEVPublished CVSS 6.5 mediumEPSS 0.3% probability of exploitation in 30 daysFound by AI: AISLE
Red Hat

CVE-2026-71225: Libkcapi: iv reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?
0.3%

Down from 0.5% on .

EPSS score, percentile 28.1 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?
6.5 Medium

CVSS v3.1 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (6)

Which versions are affected?

Affected

  • from 0.10.1 to before 1.5.1

Unaffected 0:1.5.1-1.el10_2; 0:1.5.0-6.el10_0; 0:1.4.0-3.el8_10; 0:1.4.0-3.el9_8; 0:1.4.0-2.el9_6.1; 1.5.1-0.1.hum1

Versions by product

Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.

What to do

Workaround (from the CVE record)

To mitigate this issue, applications using `libkcapi` should avoid the one-shot symmetric cipher APIs for inputs exceeding 64 KiB when continuous-message semantics are critical. Instead, prefer the streaming interface for processing large messages, or ensure one-shot inputs remain below the internal chunking threshold to guarantee the IV is applied consistently throughout the operation.

Advisories and patches

This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Stephan Muelle libkcapi
StatusVersions
Affectedfrom 0.10.1 to before 1.5.1

Versions not listed are: unaffected.

Red Hat Red Hat Enterprise Linux 10
StatusVersions
Unaffected0:1.5.1-1.el10_2

Versions not listed are: affected.

Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support
StatusVersions
Unaffected0:1.5.0-6.el10_0

Versions not listed are: affected.

Red Hat Red Hat Enterprise Linux 8
StatusVersions
Unaffected0:1.4.0-3.el8_10

Versions not listed are: affected.

Red Hat Red Hat Enterprise Linux 9
StatusVersions
Unaffected0:1.4.0-3.el9_8

Versions not listed are: affected.

Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support
StatusVersions
Unaffected0:1.4.0-2.el9_6.1

Versions not listed are: affected.

Red Hat Red Hat Hardened Images
StatusVersions
Unaffected1.5.1-0.1.hum1

Versions not listed are: affected.

Red Hat Red Hat OpenShift Container Platform 4
StatusVersions

Versions not listed are: affected.

Red Hat Red Hat OpenShift Container Platform 4
StatusVersions

Versions not listed are: affected.

Versions the record lists as unaffected: 0:1.5.1-1.el10_2, 0:1.5.0-6.el10_0, 0:1.4.0-3.el8_10, 0:1.4.0-3.el9_8, 0:1.4.0-2.el9_6.1, 1.5.1-0.1.hum1.

Source: CVE List, as of . About the data.

About this vulnerability

A flaw was found in libkcapi. When performing one-shot symmetric cipher operations on large inputs (over 64 KiB) in stateful modes such as Counter (CTR) or Cipher Block Chaining (CBC), the library improperly reuses the Initialization Vector (IV) for each internal data chunk. A remote attacker could potentially exploit this by making an application that uses libkcapi process specially crafted larg…

Summary: CVE record, as of .

  • CISA has not added CVE-2026-71225 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
  • The CVE record was published on 5 Aug 2026.
  • The CVE record carries a CVSS v3.1 base score of 6.5 (Medium), given by its CNA.
  • FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.3% (percentile 28.1), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
  • CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact partial.
  • The credits in the CVE record name AISLE as finder.

Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.

Description

Libkcapi: iv reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries

A flaw was found in libkcapi. When performing one-shot symmetric cipher operations on large inputs (over 64 KiB) in stateful modes such as Counter (CTR) or Cipher Block Chaining (CBC), the library improperly reuses the Initialization Vector (IV) for each internal data chunk. A remote attacker could potentially exploit this by making an application that uses libkcapi process specially crafted large inputs. This can lead to a significant weakening of data confidentiality, as the repeated IV use can expose relationships in encrypted plaintext, and may also affect data integrity by causing incorrect cryptographic processing.

Source: CVE List, as of . About the data.

Weakness

CWE-330

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.

Timeline

DateEvent
CVE record published
CVE record last updated

References

2

Known exploited Red Hat vulnerabilities

  • CVE-2015-3246: Red Hat Libuser Race Condition Vulnerability (added )
  • CVE-2015-5287: Red Hat Automatic Bug Reporting Tool Privilege Escalation Vulnerability (added )
  • CVE-2018-14667: Red Hat JBoss RichFaces Framework Expression Language Injection Vulnerability (added )
  • CVE-2021-3560: Red Hat Polkit Incorrect Authorization Vulnerability (added )
  • CVE-2021-4034: Red Hat Polkit Out-of-Bounds Read and Write Vulnerability (added )