CVE-2026-89078VulnerabilityPublished 9 Nov 2026

Red Hat Security Advisory: ruby security update

Affects Red Hat rubySource GCVE Database

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Mentioned vulnerabilities

Authoritative record:CVE-2026-89078· Critical 9.9

Not known to be exploited · CVSS 9.9 Critical · fixed in Red Hat package updates : patch Red Hat gitlab as a priority.

Data as of 9 Nov 2026, 03:37 UTC

CVSS 3.1 base score

9.9Critical

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

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitLab)	CVSS 3.1	9.9

Patch: Available – fixed in 19.4.1, 19.3.3, 19.2.7

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

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

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: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
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: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Sep 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 8 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.

What to do

Upgrade GitLab and gitlab to 19.4.1, 19.3.3 or 19.2.7.

Affected software

Product	Affected	Fixed in
GitLabGitLab	Affected >=19.4 <19.4.1	Fixed in 19.4.1
GitLabGitLab	Affected >=19.3 <19.3.3	Fixed in 19.3.3
GitLabGitLab	Affected >=19.2 <19.2.7	Fixed in 19.2.7
RubyGemsgitlab`pkg:gem/gitlab`Other threats	Affected >=19.2 <19.2.7 >=19.3 <19.3.3 >=19.4 <19.4.1	Fixed in 19.2.7 19.3.3 19.4.1

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 Ruby packages that fix these vulnerabilities. Users of affected Red Hat Enterprise Linux 9.8 Extended Update Support and related products should apply the updates as described in Red Hat advisory RHSA-2026:96067 and the referenced article https://access.redhat.com/articles/11258. No additional mitigation steps are indicated by the vendor.

Description

Multiple security vulnerabilities have been identified in the Ruby programming language, including a double free issue and several integer overflow issues in the regular expression parser and compiler. These vulnerabilities affect Ruby as packaged in Red Hat Enterprise Linux 9.8 Extended Update Support and related Red Hat products. The issues have been rated with moderate severity by Red Hat Product Security. Updates addressing these vulnerabilities are available through Red Hat advisories.

Impact

The vulnerabilities involve memory management errors (double free) and integer overflows in Ruby's regular expression processing components. Such flaws can lead to crashes or potentially exploitable conditions, though no active exploitation has been reported. Red Hat rates the overall security impact as Moderate. No CVSS scores are provided in the advisory. The impact is limited to systems running affected Ruby versions on Red Hat Enterprise Linux 9.8 Extended Update Support and related products.

Summary

This advisory addresses four security flaws in Ruby: a double free vulnerability in the regular expression parser (CVE-2026-89078) and three integer overflow vulnerabilities in the regular expression compiler components (CVE-2026-93577, CVE-2026-97229, CVE-2026-110264). These flaws could potentially lead to memory corruption or other unintended behavior when processing regular expressions. The vulnerabilities have been fixed in updated Ruby packages provided by Red Hat for their Enterprise Linux 9.8 Extended Update Support and related distributions. The advisory references Red Hat's errata RHSA-2026:96067 and provides links for applying the updates.

CWE-415Double Free (opens in a new tab)
Variant weaknessLikelihood of exploit: High
The product calls free() twice on the same memory address.
Architecture and Design
Choose a language that provides automatic memory management.
Implementation
Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly.
Implementation
Use a static analysis tool to find double free instances.
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-190Integer Overflow or Wraparound (opens in a new tab)
Base weaknessLikelihood of exploit: Medium
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
Requirements
Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V5.4.3 (opens in a new tab)
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
Attack patterns
Forced Integer Overflow (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 9 Nov 2026, 03:37 UTC

WeaknessesCWE-415, CWE-190

Technical details

References

Community reviews

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