CVE-2026-42945
highpriority · track · 34EPSS 0.680 · 99 %ileexploit · PoCDEEUNLRUUSEPSS · scored 2026-10-27
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when the rewrite directive is followed by a rewrite, if, or set directive and an unnamed Perl-Compatible Regular Expression (PCRE) capture (for example, $1, $2) with a replacement string that includes a question mark (?). An unauthenticated attacker along with conditions beyond its control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow 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.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- FixedHitachi Energy e-mesh EMScisa_csaf_ot
Apply hotfix for respective e-mesh EMS versions to update NGINX to either v1.30.2 or latest
- MitigationHitachi Energy e-mesh EMScisa_csaf_ot
Ensure rewrite configuration does not contain "?" to replace unnamed captures, and ensure ASLR is set to active (value=2) across all deployment targets covering all 3 versions.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 8.1–9.2
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
exploits (46)
Public proof-of-concept and weaponised exploit code.
- 0xBlackash/CVE-2026-42945CVE-2026-42945PoC · poc_in_github
affected products (51)
Products and version ranges known to be affected.
advisories (6)
Vendor and ecosystem advisories describing this.
- NCSC-2026-0164Kwetsbaarheid verholpen in NGINX ngx_http_rewrite_moduleNL2026-05-18csaf · ncsc_nlNL
NGINX heeft een kwetsbaarheid verholpen in het ngx_http_rewrite_module, onderdeel van zowel NGINX Plus als de Open Source editie.
- WID-SEC-W-2026-1527NGINX Open Source and NGINX Plus: Mehrere SchwachstellenDeutsch2026-05-14csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in NGINX Open Source and NGINX Plus ausnutzen, um Sicherheitsvorkehrungen zu umgehen, beliebigen Code auszuführen, Daten zu manipulieren, vertrauliche Informationen offenzulegen oder einen Denial-of-Service-Zustand zu verursachen.
- WID-SEC-W-2026-2933Splunk SOAR: Mehrere SchwachstellenDeutsch2026-08-19csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Splunk SOAR ausnutzen, um Sicherheitsvorkehrungen zu umgehen, um Informationen offenzulegen, um Dateien zu manipulieren, um einen SQL-Injection Angriff durchzuführen, um einen Cross-Site Scripting Angriff durchzuführen, und um beliebigen Programmcode auszuführen.
- ICSA-26-188-03Hitachi Energy e-mesh EMS2026-06-30icsa · cisa_csaf_otUS
Hitachi Energy is aware of a buffer overflow vulnerability that affects e-mesh EMS product versions listed in this document. Successful exploitation of this vulnerability could lead to a buffer overflow condition, potentially resulting in application outages (denial of service) and possible arbitrary code execution. Please refer to the Recommended Immediate Actions for information about the mitigation/remediation.
- BIT-nginx-2026-42945NGINX ngx_http_rewrite_module vulnerability2026-05-15vendor · osvUS
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when the rewrite directive is followed by a rewrite, if, or set directive and an unnamed Perl-Compatible Regular Expression (PCRE) capture (for example, $1, $2) with a replacement string that includes a question mark (?). An unauthenticated attacker along with conditions beyond its control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow 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.
- BIT-nginx-gateway-2026-42945NGINX ngx_http_rewrite_module vulnerability2026-05-15vendor · osvUS
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when the rewrite directive is followed by a rewrite, if, or set directive and an unnamed Perl-Compatible Regular Expression (PCRE) capture (for example, $1, $2) with a replacement string that includes a question mark (?). An unauthenticated attacker along with conditions beyond its control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow 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.
also known as (6)
Other names and identifiers for this entity.
- CNNVD-202605-3149cnnvd
- EUVD-2026-30010enisa_euvd
- BDU:2026-06827fstec_bdu
- GHSA-gcgv-v5gf-c543enisa_euvd
- BIT-nginx-2026-42945osv
- BIT-nginx-gateway-2026-42945osv
sources
Which sources assert this record, and when.
references (40)
External citations — patches, advisories, analysis.
- https://depthfirst.com/nginx-riftcnnvd
- https://github.com/DepthFirstDisclosures/Nginx-Riftcnnvd
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42945cnnvd
- https://my.f5.com/manage/s/article/K000161019cnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2026-42945cnnvd
- https://my.f5.com/manage/s/article/K000161019enisa_euvd
- https://access.redhat.com/errata/RHSA-2026:17417nvd
- https://access.redhat.com/errata/RHSA-2026:17751nvd
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