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TI-2026-53059 Aliases CVE-2026-75804GHSA-gjmh-wx93-r4pw

QUIC Connection-Level Flow Control is Not Enforced for Streams

Priority LOW 31CWE-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 · Low
Fix status
Partial Red Hat: 1 fixed, 13 without a fix

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

Summary

Issue summary: OpenSSL QUIC stack does not enforce connection level flow control for streams. Remote peers may send more bytes as long as they fit within the stream flow control limits. Impact summary: A malicious remote peer may exploit the lack of connection flow control for streams to make the QUIC stack receive ~100MB of memory instead of 768 KiB (default flow control window size). CWE: CWE-770: Allocation of Resources Without Limits or Throttling Description: The local QUIC stack advertises two flow control limits to its remote peer: stream flow control limit and connection flow control limit. The remote peer must follow both limits when transmitting stream data. Whenever the local QUIC stack receives a stream frame, it validates that the size of the received stream frame stays within flow control limits. If either limit is exceeded (stream level or connection level), then the QUIC stack must close the connection with a flow control error. The vulnerable OpenSSL QUIC stack enforces the stream-level but not the connection-level limit. To exploit the issue, three conditions must be met: - the remote peer opens several streams - each stream must stay within the stream-level flow control limit - there must be no zero-offset byte sent on any of the streams (to prevent the vulnerable QUIC stack from consuming data). By meeting the conditions above, the remote peer may make the local stack allocate 2 x MAX_STREAMS x (stream flow control limit) bytes of memory. MAX_STREAMS defaults to 100, and the limit applies to both bidirectional and unidirectional streams, making it 200 in total. The default flow control window for a stream is 512kB. The remote peer may force the vulnerable QUIC stack to allocate 100MB of heap per connection. 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 0.00529 45th percentileScored 2026-11-07
Fix Partial OpenSSL (OpenSSL): 4.0.3, 3.6.5, 3.5.9 +1Red Hat: 2 advisoriesRed Hat: 1 fixed, 13 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
OpenShift Developer Tools and ServicesAffectedNo fix yet
Red Hat Developer Hub 1AffectedNo fix yet
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 6AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 7AffectedNo fix yet
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat Hardened ImagesAffectedNo fix yet: Fix deferred
Red Hat JBoss Core ServicesAffectedNo fix yet
Red Hat OpenShift AI (RHOAI)Affected—
Red Hat OpenShift Container Platform 4AffectedNo fix yet
Red Hat OpenShift Container Platform 5AffectedNo fix yet
Red Hat OpenShift Dev SpacesAffectedNo fix yet: Fix deferred
Red Hat Hardened ImagesFixed RHSA-2026:74162, RHSA-2026:74166
Not affected: 4 products
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat OpenShift AI (RHOAI)
  • Red Hat Satellite 6

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-75804
  2. 2026-10-03 Alias added: GHSA-gjmh-wx93-r4pw
  3. 2026-10-06 Affected versions changed · Red Hat
  4. 2026-10-09 Affected versions changed · Red Hat
  5. 2026-10-09 CVSS score changed · Red Hat
  6. 2026-10-16 Affected versions changed · Red Hat
  7. 2026-10-20 Affected versions changed · Red Hat
  8. 2026-10-21 Affected versions changed · Red Hat
  9. 2026-10-27 Affected versions changed · Red Hat
  10. 2026-10-30 Affected versions changed · Red Hat
  11. 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