CVE-2026-71225VulnerabilityPublished 5 Aug 2026Updated 22 Oct 2026

libkcapi · Weak Randomness

Affects libkcapiSource GCVE Database

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Authoritative record:CVE-2026-71225· Medium 6.5

Not known to be exploited · CVSS 6.5 Medium.

Data as of 3 Nov 2026, 22:58 UTC

CVSS 3.1 base score

6.5Medium

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (redhat)	CVSS 3.1	6.5

EPSS: 0.3% chance of exploitation in 30 days – higher than 28% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 5 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-qv62-qmw8-96h9

What to do

Affected software

Product	Affected	Fixed in
Ubuntu 26.10libkcapi`pkg:deb/ubuntu/libkcapi?arch=source&distro=stonking`Other threats	Affected =1.4.0-1ubuntu5	Fixed in–
Ubuntu 26.04 LTSlibkcapi`pkg:deb/ubuntu/libkcapi?arch=source&distro=resolute`Other threats	Affected =1.4.0-1ubuntu4 =1.4.0-1ubuntu5	Fixed in–
Ubuntu 24.04 LTSlibkcapi`pkg:deb/ubuntu/libkcapi?arch=source&distro=noble`Other threats	Affected =1.4.0-1ubuntu3 =1.4.0-1ubuntu4	Fixed in–
Ubuntu 22.04 LTSlibkcapi`pkg:deb/ubuntu/libkcapi?arch=source&distro=jammy`Other threats	Affected 1.2.1-1 – 1.4.0-1 5 affected builds	Fixed in–
Ubuntu Pro FIPS-preview 22.04 LTSlibkcapi`pkg:deb/ubuntu/libkcapi?arch=source&distro=fips-preview/jammy`Other threats	Affected =1.4.0-1ubuntu0.1~Fips1	Fixed in–
Ubuntu Pro FIPS-updates 22.04 LTSlibkcapi`pkg:deb/ubuntu/libkcapi?arch=source&distro=fips-updates/jammy`Other threats	Affected =1.4.0-1ubuntu0.1~Fips1	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

The vendor recommends avoiding the use of one-shot symmetric cipher APIs for large inputs (over 64 KiB) in stateful modes such as CTR or CBC. Instead, use streaming cipher interfaces that correctly manage Initialization Vectors to mitigate the risk.

Description

A vulnerability in the libkcapi library affects one-shot symmetric cipher operations on large inputs over 64 KiB in stateful modes such as CTR or CBC. The flaw involves improper reuse of the Initialization Vector (IV) for each internal data chunk, weakening data confidentiality and potentially affecting data integrity. Multiple versions of libkcapi are impacted. No official patch fix is currently available, but mitigation involves avoiding one-shot symmetric cipher APIs for large inputs and using streaming interfaces instead.

Impact

The vulnerability weakens data confidentiality by reusing the Initialization Vector (IV) improperly during encryption of large inputs in stateful cipher modes, potentially allowing attackers to compromise encrypted data confidentiality and possibly affect data integrity. There is no indication of availability impact. The CVSS score is 6.5 (medium severity), reflecting high confidentiality impact and low integrity impact.

CWE-330Use of Insufficiently Random Values (opens in a new tab)
Class weaknessLikelihood of exploit: HighOWASP Top 10 A04:2025: Cryptographic Failures (opens in a new tab)
The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design
Use a well-vetted algorithm that is currently considered to be strong by experts in the field, and select well-tested implementations with adequate length seeds.
Implementation
Consider a PRNG that re-seeds itself as needed from high quality pseudo-random output sources, such as hardware devices.
Architecture and Design · Requirements · Libraries or Frameworks
Use products or modules that conform to FIPS 140-2 to avoid obvious entropy problems. Consult FIPS 140-2 Annex C ("Approved Random Number Generators").
OWASP Cheat Sheets
Forgot Password (opens in a new tab)
Transport Layer Protection (opens in a new tab)
User Privacy Protection (opens in a new tab)
Password Storage (opens in a new tab)
Cryptographic Storage (opens in a new tab)
OWASP ASVS 4.0.3
V2.3.1 (opens in a new tab)
V2.6.2 (opens in a new tab)
V2.7.6 (opens in a new tab)
Attack patterns
Signature Spoofing by Key Recreation (opens in a new tab)
Session Credential Falsification through Prediction (opens in a new tab)
Brute Force (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-416Use After Free (opens in a new tab)
Variant weaknessLikelihood of exploit: HighCWE Top 25 (2025): #7
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
Architecture and Design · Language Selection
Choose a language that provides automatic memory management.
Implementation · Attack Surface Reduction
When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-835Loop with Unreachable Exit Condition (Infinite Loop) (opens in a new tab)
Base weakness
The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 18 Oct 2026, 03:01 UTC

WeaknessesCWE-330, CWE-416, CWE-835

Technical details

References

Community reviews

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