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TI-2026-30995 Aliases CVE-2026-42772GHSA-5r49-x3jp-qp9h

Potential CPU DoS via O(n^2) Fragment Reassembly in QUIC

Priority LOW 31CWE-407Published · 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 · Low
Fix status
Partial Red Hat: 1 fixed, 7 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-407.

Summary

Issue summary: The QUIC stream reassembly algorithm performance deteriorates progressively as packets are arriving out of order. The worst case has a quadratic complexity proportional to the number of stream frames kept in the buffer for the received stream data. Impact summary: A remote QUIC peer that completes the handshake can create a connection-scoped CPU pressure and potentially a Denial of Service using compliant STREAM frames inside the advertised receive window, with low attacker bandwidth. CWE: CWE-407: Inefficient Algorithmic Complexity Description: OpenSSL manages received QUIC stream fragments using a doubly-linked list. While it optimizes for append operations (at the end of the list), it falls back to a head-to-tail linear search for any fragment that does not immediately follow the current `tail`. By manipulating the sequence of offsets, an attacker can force the server to perform O(n^2) operations, consuming excessive CPU time for the QUIC process. FIPS impact: no The FIPS module is not affected as the QUIC implementation is outside of the OpenSSL FIPS module boundary.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00497 42nd percentileScored 2026-11-07
Fix Partial OpenSSL (OpenSSL): 4.0.3, 3.6.5, 3.5.9 +1Red Hat: 2 advisoriesRed Hat: 1 fixed, 7 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
OpenSSLOpenSSL4.0.0 to before 4.0.3; 3.6.0 to before 3.6.5; 3.5.0 to before 3.5.9; 3.4.0 to before 3.4.84.0.3, 3.6.5, 3.5.9, 3.4.8Patch availableCNA
  • OpenSSL VendorOpenSSL Affected 4.0.0 to before 4.0.3; 3.6.0 to before 3.6.5; 3.5.0 to before 3.5.9; 3.4.0 to before 3.4.8 Fixed in 4.0.3, 3.6.5, 3.5.9, 3.4.8 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*3.4.0 to before 3.4.8; 3.5.0 to before 3.5.9; 3.6.0 to before 3.6.5; 4.0.0 to before 4.0.3VulnerableOpenSSL
  • cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* Versions 3.4.0 to before 3.4.8; 3.5.0 to before 3.5.9; 3.6.0 to before 3.6.5; 4.0.0 to before 4.0.3 Vulnerable ·OpenSSL

Remediation

  • Fix · CNA OpenSSL (OpenSSL) Fixed in 4.0.3, 3.6.5, 3.5.9, 3.4.8

Red Hat 2 advisories

  • RHSA-2026:74166 Released 2026-09-30 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images openssl3-1:3.5.9-0.1.hum1@src, openssl3-devel-1:3.5.9-0.1.hum1@aarch64, openssl3-devel-1:3.5.9-0.1.hum1@x86_64 +4
  • RHSA-2026:74162 Released 2026-09-30 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images openssl-1:3.5.9-0.1.hum1@aarch64, openssl-1:3.5.9-0.1.hum1@src, openssl-1:3.5.9-0.1.hum1@x86_64 +12

Fixed in the same release

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

  • Advisory ·

    OpenSSL — openssl-library.org/news/secadv/20260929.txt

    14 records Highest priority Priority MEDIUM 3 MEDIUM, 11 LOW

    Other records, highest priority first

    • TI-2026-58283 DTLS Retransmits Handshake Messages From a Stale Buffer OffsetPriority MEDIUM 43
    • TI-2026-58285 QUIC: Unbounded RETIRE_CONNECTION_ID BacklogPriority MEDIUM 40
    • TI-2026-39654 QUIC STREAM Fragment Metadata DoSPriority MEDIUM 40
    Show all 14 records → Advisory →

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Developer Hub 1AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat OpenShift AI (RHOAI)Affected—
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 5AffectedNo fix yet: Fix deferred
Red Hat Satellite 6AffectedNo fix yet: Fix deferred
Red Hat Hardened ImagesFixed RHSA-2026:74162, RHSA-2026:74166
Not affected: 6 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Hardened Images
  • Red Hat JBoss Core Services
  • Red Hat OpenShift AI (RHOAI)

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-42772
  2. 2026-10-03 Alias added: GHSA-5r49-x3jp-qp9h
  3. 2026-10-16 Affected versions changed · Red Hat
  4. 2026-10-21 Affected versions changed · Red Hat
  5. 2026-10-27 Affected versions changed · Red Hat
  6. 2026-10-30 Affected versions changed · Red Hat
  7. 2026-11-06 Affected versions changed · Red Hat

References

Patch 4

Advisory 1

  • TI-2022-01915 The c_rehash script allows command injection CVSS 3.1CRITICAL 9.8
  • TI-2021-02645 SM2 Decryption Buffer Overflow CVSS 3.1CRITICAL 9.8
  • TI-2009-03392 The TLS protocol, and the SSL protocol 3.0 and possibly earlier, as used in Microsoft… CVSS 3.1CRITICAL 9.8
  • TI-2022-01176 The c_rehash script allows command injection CVSS 3.1CRITICAL 9.8
  • TI-2014-00154 The (1) TLS and (2) DTLS implementations in OpenSSL 1.0.1 before 1.0.1g do not properly… KEVCVSS 3.1HIGH 7.5
  • TI-2025-14107 Stack buffer overflow in CMS (Auth)EnvelopedData parsing CVSS 3.1HIGH 8.8
See all 312 →

Sources

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