CVE-2026-42530: CWE-416 Use After Free in F5 NGINX Open Source
NGINX Open Source has a vulnerability in the ngx_http_v3_module module. When NGINX Open Source is configured to use the HTTP/3 QUIC module, a remote unauthenticated attacker along with conditions beyond their control can use a specially crafted HTTP/3 session to reopen a QPACK encoder stream. This may cause a Use-after-Free in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
AI Analysis
Technical Summary
NGINX Open Source 1.31.0 contains a use-after-free vulnerability (CWE-416) in the ngx_http_v3_module when configured with HTTP/3 QUIC. A remote unauthenticated attacker can send a specially crafted HTTP/3 session to reopen a QPACK encoder stream, leading to use-after-free in the worker process. This results in a denial of service via worker restart and potentially remote code execution on systems without effective ASLR protection. No official patch or remediation level has been published yet, and no known exploits are reported in the wild.
Potential Impact
Successful exploitation can cause the NGINX worker process to restart, resulting in denial of service. On systems where ASLR is disabled or bypassed, attackers may achieve remote code execution, compromising system integrity and confidentiality.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, consider disabling the HTTP/3 QUIC module if feasible or applying network-level protections to limit exposure to untrusted clients.
CVE-2026-42530: CWE-416 Use After Free in F5 NGINX Open Source
Description
NGINX Open Source has a vulnerability in the ngx_http_v3_module module. When NGINX Open Source is configured to use the HTTP/3 QUIC module, a remote unauthenticated attacker along with conditions beyond their control can use a specially crafted HTTP/3 session to reopen a QPACK encoder stream. This may cause a Use-after-Free in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
CVSS v3.1
Score 8.1high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
NGINX Open Source 1.31.0 contains a use-after-free vulnerability (CWE-416) in the ngx_http_v3_module when configured with HTTP/3 QUIC. A remote unauthenticated attacker can send a specially crafted HTTP/3 session to reopen a QPACK encoder stream, leading to use-after-free in the worker process. This results in a denial of service via worker restart and potentially remote code execution on systems without effective ASLR protection. No official patch or remediation level has been published yet, and no known exploits are reported in the wild.
Potential Impact
Successful exploitation can cause the NGINX worker process to restart, resulting in denial of service. On systems where ASLR is disabled or bypassed, attackers may achieve remote code execution, compromising system integrity and confidentiality.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, consider disabling the HTTP/3 QUIC module if feasible or applying network-level protections to limit exposure to untrusted clients.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- f5
- Date Reserved
- 2026-06-02T21:45:04.719Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a32b82c9f87a2db090fd5e8
Added to database: 6/17/2026, 3:07:24 PM
Last enriched: 6/17/2026, 3:09:16 PM
Last updated: 6/17/2026, 4:14:30 PM
Views: 4
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