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.
CVE-2026-42945
“▲” beside the score: it is higher than the CVSS score beside it.
Score elevated to 8.7 because EPSS predicted 68% probability of exploitation within the next 30 days (99th percentile of EPSS-scored CVEs) when EchelonGraph scored this CVE. A secondary CVSS source baseline 8.1 retained for reference (NVD's own analysis pending). Confidence: see factors.
Also known asEUVD-2026-30010 (ENISA EUVD) · GHSA-gcgv-v5gf-c543 (GitHub Security Advisories)Source: ENISA EUVD
- High exploitation likelihood — EPSS 68%
- Public exploit or proof-of-concept code is available
A fix is available — apply it.
- CVSS v3
- 8.1
- EG Score
- 8.7HIGHhigh confidence
- EG Risk
- 64EG Risk 64/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity81% × 45%Impact severity (EG Severity): CVSS 8.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation68% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it within your standard update timelines. - EPSS PROB
- 68%
- EPSS %ILE
- 99th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (8.7): severity, escalated by confirmed exploitation. This CVE's 8.7 is EPSS's lift toward 9.0 from its impact severity (EG Severity, CVSS 8.1 HIGH): a likelihood of exploitation, not impact.
- EG Severity
- 8.1 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 68% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-27). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
May 13, 2026
Last Modified
October 26, 2026
Advisory Details (1)
Auto-updated May 13, 2026Vendor Advisories for CVE-2026-42945(20)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:58981Red Hat Product SecurityCritical
Red Hat Security Advisory: Red Hat Update Infrastructure 5.3 Technology Preview security update
- RHSA-2026:22396Red Hat Product SecurityCritical
Red Hat Security Advisory: Red Hat OpenShift Data Foundation 4.14.33 security, enhancement & bug fix update
- RHSA-2026:22394Red Hat Product SecurityCritical
Red Hat Security Advisory: Red Hat OpenShift Data Foundation 4.16.29 security, enhancement & bug fix update
- RHSA-2026:22393Red Hat Product SecurityCritical
Red Hat Security Advisory: Red Hat OpenShift Data Foundation 4.15.29 security, enhancement & bug fix update
- RHSA-2026:22390Red Hat Product SecurityCritical
Red Hat Security Advisory: Red Hat OpenShift Data Foundation 4.17.27 security, enhancement & bug fix update
- RHSA-2026:22389Red Hat Product SecurityCritical
Red Hat Security Advisory: Red Hat OpenShift Data Foundation 4.19.18 security, enhancement & bug fix update
- RHSA-2026:22388Red Hat Product SecurityCritical
Red Hat Security Advisory: Red Hat OpenShift Data Foundation 4.18.23 security, enhancement & bug fix update
- RHSA-2026:22383Red Hat Product SecurityCritical
Red Hat Security Advisory: Red Hat OpenShift Data Foundation 4.20.13 security, enhancement & bug fix update
- +12 more
Patch Availability(30)
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(8 across 8 ecosystems)
Alpine:v3.21(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| nginx | — |
| — |
Alpine:v3.22(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| nginx | — |
| — |
Alpine:v3.23(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| nginx | — |
| — |
Alpine:v3.24(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| nginx | — |
| — |
Debian:11(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| nginx | 1.18.0-6.1 ... 1.18.0-6.1+deb11u5 (6 versions) |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| nginx | 1.22.1-9 ... 1.22.1-9+deb12u6 (7 versions) |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| nginx | 1.26.3-3, 1.26.3-3+deb13u1, 1.26.3-3+deb13u2, 1.26.3-3+deb13u3, 1.26.3-3+deb13u4 |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| nginx | 1.26.3-3 ... 1.30.0-2 (18 versions) |
| — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(9)
Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.
- Red HatRHSA-2026:17417CRITICAL2026-05-13
RHSA-2026:17417 — Critical
- Red HatRHSA-2026:17751CRITICAL2026-05-13
RHSA-2026:17751 — Critical
- Red HatRHSA-2026:17752CRITICAL2026-05-13
RHSA-2026:17752 — Critical
- Red HatRHSA-2026:17753CRITICAL2026-05-13
RHSA-2026:17753 — Critical
- Red HatRHSA-2026:17790CRITICAL2026-05-13
RHSA-2026:17790 — Critical
- Red HatRHSA-2026:17791CRITICAL2026-05-13
RHSA-2026:17791 — Critical
- Red HatRHSA-2026:17792CRITICAL2026-05-13
RHSA-2026:17792 — Critical
- Red HatRHSA-2026:17793CRITICAL2026-05-13
RHSA-2026:17793 — Critical
- Red HatRHSA-2026:17794CRITICAL2026-05-13
RHSA-2026:17794 — Critical
Data Freshness Timeline
(refreshed 7× in last 7d / 46× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 100 of 341 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 241 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-31 16:32 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-10-30 16:34 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-10-29 16:33 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-10-27 21:00 UTCEG score recompute
- 2026-10-27 21:00 UTCVendor advisory
- 2026-10-27 21:00 UTCGHSA enrichmentGHSA-gcgv-v5gf-c543 · GitHub severity CRITICAL · GitHub CVSS 8.1
- 2026-10-27 16:32 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-10-26 14:37 UTCEG score recompute
- 2026-10-26 14:37 UTCVendor advisory
- 2026-10-26 14:37 UTCGHSA enrichmentGHSA-gcgv-v5gf-c543 · GitHub severity CRITICAL · GitHub CVSS 8.1
- 2026-10-25 16:36 UTCEG score recompute▲ 0.60
- 2026-10-25 16:36 UTCVendor advisory
- 2026-10-25 16:36 UTCGHSA enrichmentGHSA-gcgv-v5gf-c543 · GitHub severity CRITICAL · GitHub CVSS 8.1
- 2026-10-25 16:33 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-10-25 14:28 UTCEG score recompute
- 2026-10-24 16:33 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-23 16:31 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-22 16:34 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-21 16:33 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-18 16:51 UTCEG score recompute
- 2026-10-18 16:51 UTCVendor advisory
- 2026-10-18 16:51 UTCGHSA enrichmentGHSA-gcgv-v5gf-c543 · GitHub severity CRITICAL · GitHub CVSS 8.1
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 3.4% · 88th percentile
Show 75 moreShow fewer
- 2026-10-18 03:40 UTCEG score recompute
- 2026-10-17 16:34 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-17 14:17 UTCEG score recompute
- 2026-10-17 14:17 UTCVendor advisory
- 2026-10-17 14:17 UTCGHSA enrichmentGHSA-gcgv-v5gf-c543 · GitHub severity CRITICAL · GitHub CVSS 8.1
- 2026-10-16 16:42 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-15 16:32 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-14 16:33 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-13 16:34 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-12 16:06 UTCEG score recompute
- 2026-10-11 19:48 UTCEG score recompute
- 2026-10-11 17:03 UTCEG score recompute
- 2026-10-11 14:29 UTCEG score recompute▼ 0.60
- 2026-10-11 13:48 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-08 17:12 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-06 15:17 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-05 17:43 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-03 14:25 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-01 19:50 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-09-30 15:03 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-09-29 20:02 UTCOSV refresh
- 2026-09-27 13:48 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-09-26 15:58 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-09-17 19:31 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-09-16 14:08 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-09-16 05:15 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-09-13 16:47 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-09-12 15:01 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-09-11 14:53 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-09-10 13:40 UTCEG score recompute
- 2026-09-10 13:40 UTCVendor advisory
- 2026-09-10 13:39 UTCGHSA enrichmentGHSA-gcgv-v5gf-c543 · GitHub severity CRITICAL · GitHub CVSS 8.1
- 2026-09-10 12:27 UTCEG score recompute
- 2026-09-10 12:27 UTCVendor advisory
- 2026-09-10 12:27 UTCGHSA enrichmentGHSA-gcgv-v5gf-c543 · GitHub severity CRITICAL · GitHub CVSS 8.1
- 2026-09-10 09:34 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-09-09 13:41 UTCEG score recompute
- 2026-09-09 13:41 UTCVendor advisory
- 2026-09-09 13:41 UTCGHSA enrichmentGHSA-gcgv-v5gf-c543 · GitHub severity CRITICAL · GitHub CVSS 8.1
- 2026-09-09 12:39 UTCEG score recompute
- 2026-09-09 12:39 UTCVendor advisory
- 2026-09-09 12:39 UTCGHSA enrichmentGHSA-gcgv-v5gf-c543 · GitHub severity CRITICAL · GitHub CVSS 8.1
- 2026-09-08 22:00 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-09-07 16:01 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-09-07 13:57 UTCEG score recompute
- 2026-09-07 13:57 UTCVendor advisory
- 2026-09-07 13:56 UTCGHSA enrichmentGHSA-gcgv-v5gf-c543 · GitHub severity CRITICAL · GitHub CVSS 8.1
- 2026-09-07 12:45 UTCEG score recompute
- 2026-09-07 12:45 UTCVendor advisory
- 2026-09-07 12:45 UTCGHSA enrichmentGHSA-gcgv-v5gf-c543 · GitHub severity CRITICAL · GitHub CVSS 8.1
- 2026-09-06 13:47 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-09-04 05:06 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-09-02 14:12 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-08-30 19:17 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-08-30 01:22 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-08-28 21:41 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-08-26 14:46 UTCEPSS rescoreEPSS 68% · 99th percentile
- 2026-08-25 13:24 UTCEG score recompute
- 2026-08-25 13:24 UTCVendor advisory
- 2026-08-25 13:24 UTCGHSA enrichmentGHSA-gcgv-v5gf-c543 · GitHub severity CRITICAL · GitHub CVSS 8.1
- 2026-08-25 12:21 UTCEG score recompute
- 2026-08-25 12:21 UTCVendor advisory
- 2026-08-25 12:21 UTCGHSA enrichmentGHSA-gcgv-v5gf-c543 · GitHub severity CRITICAL · GitHub CVSS 8.1
- 2026-08-24 12:26 UTCEG score recompute
- 2026-08-24 12:26 UTCVendor advisory
- 2026-08-24 12:25 UTCGHSA enrichmentGHSA-gcgv-v5gf-c543 · GitHub severity CRITICAL · GitHub CVSS 8.1
- 2026-08-23 17:54 UTCEG score recompute
- 2026-08-23 17:54 UTCVendor advisory
- 2026-08-23 17:54 UTCGHSA enrichmentGHSA-gcgv-v5gf-c543 · GitHub severity CRITICAL · GitHub CVSS 8.1
- 2026-08-21 23:49 UTCEPSS rescoreEPSS 66% · 99th percentile
Publicly available exploits
(14 references, 10 shown)Public exploit code is referenced for this CVE (12 GitHub PoCs), as are 2 GitHub checker repositories. A GitHub repository named or described as a checker or scanner checks whether a system is affected; it is not necessarily exploit code. Defenders should treat patch urgency accordingly.
- GitHub PoCbamov970/CVE-2026-42945-Nginx-RCE-bypass-ASLRPublished May 25, 2026
CVE-2026-42945 turns a 17-year-old NGINX rewrite bug into remote code execution — even with ASLR on, by chaining the heap overflow with live worker memory read through a common file-read flaw.
Open source ↗ - GitHub PoCnu0l/NGINX-RiftPublished May 25, 2026
CVE-2026-42945 NGINX 堆溢出漏洞扫描与验证工具
Open source ↗ - GitHub PoCgagaltotal/CVE-2026-42945-NGINX-Rift-ToolkitPublished May 20, 2026
CVE-2026-42945 - NGINX Rift Toolkit
Open source ↗ - GitHub PoCtal7aouy/nginx-cve-2026-42945Published May 17, 2026
🛡️ Script to test for NGINX CVE-2026-42945
Open source ↗ - GitHub PoCMateusVerass/nGixshellPublished May 16, 2026
nginx CVE scanner + RCE exploit framework (CVE-2026-42945 + 16 others)
Open source ↗ - GitHub checkeroseasfr/Scanner_CVE_2026-42945Published May 15, 2026
Script Python para detecção de instâncias Nginx vulneráveis ao CVE-2026-42945 em IPs, CIDRs e ASNs.
Open source ↗ - GitHub PoCiammerrida-source/nginx-rift-detectPublished May 15, 2026
Behavioral detection script for CVE-2026-42945 (NGINX Rift) — heap overflow in ngx_http_rewrite_module. No RCE, crash-based detection only.
Open source ↗ - Open source ↗GitHub PoCjelasin/CVE-2026-42945Published May 15, 2026
- GitHub checkerfriparia/NGINX_RIFT_SCAN_CVE_2026_42945Published May 14, 2026
Nginx Rewrite CVE Scan(CVE-2026-42945 nginx-rift CVE-2026-9256)
Open source ↗ - GitHub PoCcipherspy/CVE-2026-42945-POCPublished May 14, 2026
exploit for CVE-2026-42945
Open source ↗
Related CVEs(same product + same vendor + same CWE)
Same product
10 shownAlpine:v3.21:nginx
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- CVE-2019-9513NVD 7.5EG 8.9EPSS p100HIGH
- CVE-2017-7529NVD 7.5EG 8.4EPSS p99HIGH
- CVE-2019-9511NVD 7.5EG 8.3EPSS p99HIGH
- CVE-2026-60005EG 8.2HIGH
- CVE-2026-42533EG 8.1EPSS p94HIGH
- CVE-2026-42055EG 8.1EPSS p94HIGH
- CVE-2026-9256EG 8.1EPSS p96HIGH
- CVE-2018-16843NVD 7.5EG 8.0EPSS p99HIGH
Same vendor
10 shownredhat:RHSA-2026:21275 · redhat:RHSA-2026:58981
Frequently asked(5)
What is CVE-2026-42945?
When was CVE-2026-42945 made public?
Is CVE-2026-42945 actively exploited?
What is the CVSS score of CVE-2026-42945?
How do I remediate CVE-2026-42945?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-42945
Is Your Infrastructure Affected by CVE-2026-42945?
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