CVE-2025-68156VulnerabilityPublished 9 Feb 2026Updated 6 Sep 2026

Red Hat Security Advisory: Custom Metrics Autoscaler Operator for Red Hat OpenShift 2.18.1-2 Update

Affects Red HatSource GCVE Database

Authoritative record:CVE-2025-68156· High 7.5

Not known to be exploited · CVSS 7.5 High : upgrade Red Hat to 1.17.7 soon.

Data as of 26 Oct 2026, 09:15 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 36% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.17.7

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

Exploitation evidence

Disclosed: evidence found.
CVE published 16 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC 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.

What to do

Upgrade github.com/expr-lang/expr to 1.17.7.

Affected software

Product	Affected	Fixed in
Gogithub.com/expr-lang/expr`pkg:golang/github.com/expr-lang/expr`Other threats	Affected <1.17.7	Fixed in 1.17.7

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

AI-suggested

Red Hat has released updated Custom Metrics Autoscaler Operator images based on KEDA 2.18.1 that address this vulnerability. Users should apply these updates after ensuring all prior relevant errata are applied. Additionally, applications should validate or sanitize externally supplied data structures to prevent cyclic references before passing them to Expr for evaluation. Wrapping expression evaluation with panic recovery can also help prevent full process crashes. Follow Red Hat's official update instructions at https://access.redhat.com/articles/11258.

Description

The Custom Metrics Autoscaler Operator for Red Hat OpenShift is an optional operator, based on the Kubernetes Event Driven Autoscaler (KEDA), which allows workloads to be scaled using additional metrics sources other than pod metrics. This release is based upon KEDA 2.18.1

Impact

Successful exploitation can cause a denial of service by crashing the application through stack overflow. This impacts availability but does not affect confidentiality or integrity. Only applications that evaluate expressions against untrusted or insufficiently validated data structures using the Expr library are affected.

Summary

CVE-2025-68156 is a denial of service vulnerability in the Expr Go library used by the Custom Metrics Autoscaler Operator for Red Hat OpenShift. The vulnerability arises from uncontrolled recursion during expression evaluation of user-provided data structures that are deeply nested or cyclic, leading to stack overflow and application crash. This affects Red Hat products that utilize the Expr library and evaluate expressions against untrusted or insufficiently validated data. The vulnerability is rated important due to its potential to cause denial of service. Mitigations include validating or sanitizing input data structures to avoid cyclic references and wrapping expression evaluation with panic recovery. Red Hat has released updated operator images based on KEDA 2.18.1 to address this issue.

CWE-770Allocation of Resources Without Limits or Throttling (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #25
The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
Requirements
Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
Architecture and Design
Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V8.1.4 (opens in a new tab)
V13.4.1 (opens in a new tab)
V11.1.4 (opens in a new tab)
Attack patterns
XML Ping of the Death (opens in a new tab)
Exponential Data Expansion (opens in a new tab)
Serialized Data Parameter Blowup (opens in a new tab)
Serialized Data with Nested Payloads (opens in a new tab)
Oversized Serialized Data Payloads (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #6OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…
Implementation · Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174).
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.3.1 (opens in a new tab)
Attack patterns
Path Traversal (opens in a new tab)
Using Slashes and URL Encoding Combined to Bypass Validation Logic (opens in a new tab)
Manipulating Web Input to File System Calls (opens in a new tab)
Using Escaped Slashes in Alternate Encoding (opens in a new tab)
Using Slashes in Alternate Encoding (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 10 Aug 2026, 20:34 UTC

WeaknessesCWE-770, CWE-22

Technical details

References

Community reviews

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