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TI-2026-55453 Aliases CVE-2026-80212GHSA-x2vh-ff4w-v64c

Resource allocation without limits in ruby resolv

Priority LOW 39CWE-770Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 18 fixed, 3 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-770.

Summary

An issue was discovered in the resolv gem before 0.7.2 for Ruby. Resolv::DNS::Resource.get_class, Resolv::DNS::Resource::Generic.create, and Resolv::DNS::SvcParam::Generic.create generate a new class for each unknown DNS resource record (type, class) pair, or each unknown SvcParamKey, encountered while decoding a response. Each generated class was permanently registered both as a constant on Resource (or SvcParam::Generic) and as an entry in a class-lookup hash (ClassHash), and thus the class remained reachable through that constant after the response was discarded. Type and class are each 16-bit values, and thus an attacker controlling DNS responses (a spoofed response, or a malicious or hijacked upstream DNS server) has roughly 2^32 distinct (type, class) pairs to choose from. A single response of a few hundred kilobytes carrying tens of thousands of distinct unknown types permanently grows process memory by tens of megabytes; repeated responses accumulate without bound and are never reclaimed by garbage collection, because the constant keeps each class alive. Any code path that calls Resolv::DNS::Message.decode on attacker-influenced DNS responses is affected. resolv is a default gem, and thus this is reachable from a plain Ruby installation without any additional dependency.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00401 34th percentileScored 2026-11-07
Fix Partial resolv (Ruby): 0.3.2, 0.7.2Red Hat: 21 advisoriesRed Hat: 18 fixed, 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
rubyresolvbefore 0.3.2; 0.4.0 to before 0.7.20.3.2, 0.7.2Patch availableCNA
  • resolv Vendorruby Affected before 0.3.2; 0.4.0 to before 0.7.2 Fixed in 0.3.2, 0.7.2 Patch available CNA

Remediation

  • Fix · CNA resolv (Ruby) Fixed in 0.3.2, 0.7.2

Red Hat 21 advisories

  • RHSA-2026:95514 Released 2026-11-05 · Red Hat rating Important
    ruby:2.5 security update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) ruby-2.5.9-113.module+el8.8.0+25037+4937972b.i686::ruby:2.5, ruby-2.5.9-113.module+el8.8.0+25037+4937972b.ppc64le::ruby:2.5, ruby-2.5.9-113.module+el8.8.0+25037+4937972b.src::ruby:2.5 +47
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) ruby-2.5.9-113.module+el8.8.0+25037+4937972b.i686::ruby:2.5, ruby-2.5.9-113.module+el8.8.0+25037+4937972b.src::ruby:2.5, ruby-2.5.9-113.module+el8.8.0+25037+4937972b.x86_64::ruby:2.5 +44
  • RHSA-2026:95513 Released 2026-11-05 · Red Hat rating Important
    ruby:2.5 security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) ruby-2.5.9-113.module+el8.6.0+25038+e1ee8198.i686::ruby:2.5, ruby-2.5.9-113.module+el8.6.0+25038+e1ee8198.src::ruby:2.5, ruby-2.5.9-113.module+el8.6.0+25038+e1ee8198.x86_64::ruby:2.5 +44
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) ruby-2.5.9-113.module+el8.6.0+25038+e1ee8198.i686::ruby:2.5, ruby-2.5.9-113.module+el8.6.0+25038+e1ee8198.src::ruby:2.5, ruby-2.5.9-113.module+el8.6.0+25038+e1ee8198.x86_64::ruby:2.5 +44
  • RHSA-2026:95512 Released 2026-11-05 · Red Hat rating Important
    ruby:2.5 security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) ruby-2.5.9-110.module+el8.4.0+25044+d8ea83a3.i686::ruby:2.5, ruby-2.5.9-110.module+el8.4.0+25044+d8ea83a3.src::ruby:2.5, ruby-2.5.9-110.module+el8.4.0+25044+d8ea83a3.x86_64::ruby:2.5 +44
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) ruby-2.5.9-110.module+el8.4.0+25044+d8ea83a3.i686::ruby:2.5, ruby-2.5.9-110.module+el8.4.0+25044+d8ea83a3.src::ruby:2.5, ruby-2.5.9-110.module+el8.4.0+25044+d8ea83a3.x86_64::ruby:2.5 +44
Show 18 more Red Hat advisories
  • RHSA-2026:86207 Released 2026-10-20 · Red Hat rating Important
    ruby:3.3 security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) ruby-3.3.12-6.module+el9.6.0+24954+a3e9682a.2.aarch64::ruby:3.3, ruby-3.3.12-6.module+el9.6.0+24954+a3e9682a.2.i686::ruby:3.3, ruby-3.3.12-6.module+el9.6.0+24954+a3e9682a.2.ppc64le::ruby:3.3 +47
  • RHSA-2026:86208 Released 2026-10-20 · Red Hat rating Important
    ruby:3.3 security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) ruby-3.3.12-7.module+el9.4.0+24953+58752046.3.aarch64::ruby:3.3, ruby-3.3.12-7.module+el9.4.0+24953+58752046.3.i686::ruby:3.3, ruby-3.3.12-7.module+el9.4.0+24953+58752046.3.ppc64le::ruby:3.3 +47
  • RHSA-2026:83571 Released 2026-10-15 · Red Hat rating Important
    ruby security update
    • Red Hat CodeReady Linux Builder EUS (v.9.6) ruby-doc-3.0.7-166.el9_6
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) ruby-3.0.7-166.el9_6, ruby-default-gems-3.0.7-166.el9_6, ruby-devel-3.0.7-166.el9_6 +18
  • RHSA-2026:83574 Released 2026-10-15 · Red Hat rating Important
    ruby security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) ruby-3.0.4-162.el9_2, ruby-default-gems-3.0.4-162.el9_2, ruby-devel-3.0.4-162.el9_2 +18
  • RHSA-2026:83572 Released 2026-10-15 · Red Hat rating Important
    ruby security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) ruby-3.0.7-163.el9_4, ruby-default-gems-3.0.7-163.el9_4, ruby-devel-3.0.7-163.el9_4 +18
  • RHSA-2026:83570 Released 2026-10-15 · Red Hat rating Important
    ruby security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) ruby-3.3.12-12.el10_0, ruby-bundled-gems-3.3.12-12.el10_0, ruby-default-gems-3.3.12-12.el10_0 +20
    • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) ruby-doc-3.3.12-12.el10_0
  • RHSA-2026:72785 Released 2026-10-02 · Red Hat rating Important
    ruby security update
    • Red Hat Enterprise Linux AppStream (v. 10) ruby-3.3.12-15.el10_2, ruby-bundled-gems-3.3.12-15.el10_2, ruby-default-gems-3.3.12-15.el10_2 +20
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) ruby-doc-3.3.12-15.el10_2
  • RHSA-2026:73519 Released 2026-09-30 · Red Hat rating Important
    ruby:2.5 security update
    • Red Hat Enterprise Linux AppStream (v. 8) ruby-2.5.9-116.module+el8.10.0+24853+52b5af56.aarch64::ruby:2.5, ruby-2.5.9-116.module+el8.10.0+24853+52b5af56.i686::ruby:2.5, ruby-2.5.9-116.module+el8.10.0+24853+52b5af56.ppc64le::ruby:2.5 +47
  • RHSA-2026:72485 Released 2026-09-28 · Red Hat rating Important
    ruby:3.3 security update
    • Red Hat Enterprise Linux AppStream (v. 9) ruby-3.3.12-9.module+el9.8.0+24851+57cc0ffc.aarch64::ruby:3.3, ruby-3.3.12-9.module+el9.8.0+24851+57cc0ffc.i686::ruby:3.3, ruby-3.3.12-9.module+el9.8.0+24851+57cc0ffc.ppc64le::ruby:3.3 +47
  • RHSA-2026:72484 Released 2026-09-28 · Red Hat rating Important
    ruby:4.0 security update
    • Red Hat Enterprise Linux AppStream (v. 9) ruby-4.0.6-35.module+el9.8.0+24852+4534d062.aarch64::ruby:4.0, ruby-4.0.6-35.module+el9.8.0+24852+4534d062.i686::ruby:4.0, ruby-4.0.6-35.module+el9.8.0+24852+4534d062.ppc64le::ruby:4.0 +47
  • RHSA-2026:72427 Released 2026-09-28 · Red Hat rating Important
    ruby4.0 security update
    • Red Hat Enterprise Linux AppStream (v. 10) ruby4.0-4.0.6-37.el10_2, ruby4.0-devel-4.0.6-37.el10_2, ruby4.0-rubygem-mysql2-0.5.7-37.el10_2 +1
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) ruby4.0-doc-4.0.6-37.el10_2
  • RHSA-2026:72286 Released 2026-09-28 · Red Hat rating Important
    ruby security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) ruby-3.0.7-168.el9_8, ruby-default-gems-3.0.7-168.el9_8, ruby-devel-3.0.7-168.el9_8 +18
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) ruby-doc-3.0.7-168.el9_8
  • RHSA-2026:72285 Released 2026-09-28 · Red Hat rating Important
    ruby:3.3 security update
    • Red Hat Enterprise Linux AppStream (v. 8) ruby-3.3.12-9.module+el8.10.0+24850+a62b5b25.aarch64::ruby:3.3, ruby-3.3.12-9.module+el8.10.0+24850+a62b5b25.i686::ruby:3.3, ruby-3.3.12-9.module+el8.10.0+24850+a62b5b25.ppc64le::ruby:3.3 +47
  • RHSA-2026:62563 Released 2026-09-02 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images ruby4.0-4.0.6-37.3.hum1@aarch64, ruby4.0-4.0.6-37.3.hum1@src, ruby4.0-4.0.6-37.3.hum1@x86_64 +46
  • RHSA-2026:62562 Released 2026-09-02 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images ruby3.3-3.3.10-23.6.hum1@aarch64, ruby3.3-3.3.10-23.6.hum1@src, ruby3.3-3.3.10-23.6.hum1@x86_64 +46
  • RHSA-2026:57994 Released 2026-08-21 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images ruby3.4-3.4.10-31.6.hum1@aarch64, ruby3.4-3.4.10-31.6.hum1@src, ruby3.4-3.4.10-31.6.hum1@x86_64 +10
  • RHSA-2026:57986 Released 2026-08-21 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images ruby3.3-3.3.10-23.5.hum1@aarch64, ruby3.3-3.3.10-23.5.hum1@src, ruby3.3-3.3.10-23.5.hum1@x86_64 +10
  • RHSA-2026:57565 Released 2026-08-20 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images ruby4.0-4.0.6-37.2.hum1@aarch64, ruby4.0-4.0.6-37.2.hum1@src, ruby4.0-4.0.6-37.2.hum1@x86_64 +46

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Ruby resolv 0.3.2, 0.7.2

    2 records Highest priority Priority LOW 2 LOW

    Other records, highest priority first

    • TI-2026-55454 An issue was discovered in the resolv gem before 0.7.2 for Ruby.Priority LOW 18
    Show all 2 records →

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Lightspeed CoreAffectedNo fix yet
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix yet
Red Hat CodeReady Linux Builder EUS (v.9.6)Fixed RHSA-2026:83571
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:72427, RHSA-2026:72785
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:72285, RHSA-2026:73519
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:72286, RHSA-2026:72484, RHSA-2026:72485
Red Hat Enterprise Linux AppStream AUS (v.8.4)Fixed RHSA-2026:95512
Red Hat Enterprise Linux AppStream AUS (v.8.6)Fixed RHSA-2026:95513
Red Hat Enterprise Linux AppStream E4S (v.8.8)Fixed RHSA-2026:95514
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:83574
Red Hat Enterprise Linux AppStream E4S (v.9.4)Fixed RHSA-2026:83572, RHSA-2026:86208
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:83570
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:83571, RHSA-2026:86207
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)Fixed RHSA-2026:95512
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6)Fixed RHSA-2026:95513
Red Hat Enterprise Linux AppStream TUS (v.8.8)Fixed RHSA-2026:95514
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:72427, RHSA-2026:72785
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:72286
Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)Fixed RHSA-2026:83570
Red Hat Hardened ImagesFixed RHSA-2026:57565, RHSA-2026:57986, RHSA-2026:57994, RHSA-2026:62562, RHSA-2026:62563
Not affected: 2 products
  • Red Hat 3scale API Management Platform 2
  • Red Hat Hardened Images

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-80212
  2. 2026-10-03 Alias added: GHSA-x2vh-ff4w-v64c
  3. 2026-10-09 Affected versions changed · Red Hat
  4. 2026-10-16 Fix available: RHSA-2026:83571 · Red Hat
  5. 2026-10-16 Fix available: RHSA-2026:83570 · Red Hat
  6. 2026-10-16 Fix available: RHSA-2026:83574 · Red Hat
  7. 2026-10-16 Fix available: RHSA-2026:83572 · Red Hat
  8. 2026-10-16 Fix available: Red Hat CodeReady Linux Builder EUS (v.9.6), Red Hat Enterprise Linux AppStream E4S (v.9.2), Red Hat Enterprise Linux AppStream E4S (v.9.4) +3 · Red Hat
  9. 2026-10-21 Fix available: RHSA-2026:86207 · Red Hat
  10. 2026-10-21 Fix available: RHSA-2026:86208 · Red Hat
  11. 2026-10-21 Affected versions changed · Red Hat
  12. 2026-11-05 Fix available: Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) +1 · Red Hat
  13. 2026-11-05 Fix available: Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) · Red Hat
  14. 2026-11-06 Fix available: RHSA-2026:95512 · Red Hat
  15. 2026-11-06 Fix available: RHSA-2026:95514 · Red Hat
  16. 2026-11-06 Fix available: RHSA-2026:95513 · Red Hat

References

Other 2

  • TI-2026-71508 Integer overflow in GitLab allows code execution on the server KEVCVSS 3.1CRITICAL 10.0
  • TI-2026-50176 Use after free in ruby json CVSS 4.0HIGH 8.7
  • TI-2017-12709 Ruby before 2.4.3 allows Net::FTP command injection. CVSS 3.0HIGH 8.8
  • TI-2008-03501 Algorithmic complexity vulnerability in the WEBrick::HTTPUtils.split_header_value… CVSS 2.0HIGH 7.8
  • TI-2021-09891 In Ruby through 3.0 on Windows, a remote attacker can submit a crafted path when a Web… CVSS 3.1HIGH 7.5
  • TI-2025-18855 Net::IMAP vulnerable to possible DoS by memory exhaustion CVSS 3.1MEDIUM 6.5
See all 135 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences