CVE-2026-80212VulnerabilityPublished 28 Sep 2026Updated 6 Nov 2026

Red Hat Security Advisory: ruby:3.3 security update

Affects Red Hat ruby:3.3Source GCVE Database

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Authoritative record:CVE-2026-80212· High 7.5

Not known to be exploited · CVSS 7.5 High : upgrade Red Hat ruby:3.3 to 0.7.2 or 0.3.2 soon.

Data as of 6 Nov 2026, 03:19 UTC

CVSS 3.1 base score

7.5High

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

Patch: Available – fixed in 0.7.2, 0.3.2

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

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

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: 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: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 27 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 5 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 resolv to 0.7.2 or 0.3.2.

Affected software

Product	Affected	Fixed in
Rubyresolv	Affected >=0.4.0 <0.7.2	Fixed in 0.7.2
Rubyresolv	Affected <0.3.2	Fixed in 0.3.2

AI-suggested

Red Hat has released an updated Ruby 3.3 module for Red Hat Enterprise Linux 8 and its extended life cycle variants that addresses this vulnerability. Users should apply the official update as described in Red Hat advisory RHSA-2026:72285 and the referenced article (https://access.redhat.com/articles/11258) to remediate the issue. No additional mitigation steps are indicated beyond applying this update.

Description

A security update for Ruby 3.3 addresses a denial of service vulnerability in the resolv gem. The flaw involves uncontrolled memory growth triggered by crafted DNS responses. This vulnerability is identified as CVE-2026-80212 and has been rated as having an important security impact by Red Hat. The update is available for Red Hat Enterprise Linux 8 and its extended life cycle variants across multiple architectures.

Impact

The vulnerability allows denial of service via uncontrolled memory growth from malicious DNS responses, potentially causing affected systems to become unresponsive or crash. No evidence of exploitation in the wild is reported. The impact is rated as important by Red Hat, indicating a significant but not critical threat to system availability.

Summary

The Ruby programming language's resolv gem is affected by a denial of service vulnerability (CVE-2026-80212) caused by uncontrolled memory growth when processing crafted DNS responses. This flaw can lead to resource exhaustion, impacting system stability. Red Hat has issued a security advisory (RHSA-2026:72285) providing an update for Ruby 3.3 modules on Red Hat Enterprise Linux 8 platforms. The advisory classifies the impact as important and directs users to apply the update to remediate the 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).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Nov 2026, 03:19 UTC

WeaknessesCWE-770

Technical details

References

Community reviews

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