CVE-2026-42945: F5 NGINX Plus · Heap-based Buffer Overflow.
Affects F5 NGINX PlusSource CVE Database V5
Not known to be exploited · 68% EPSS · CVSS 8.1 High : upgrade to 1.30.1 as a priority.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 68.0% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.30.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 13 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
Public exploit code: GitHub proofs of concept
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), GitHub proofs of concept, the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade NGINX Open Source to 1.30.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| F5NGINX Plus | Affected
| Fixed in– |
| F5NGINX Open Source | Affected
| Fixed in
|
AI-suggested
Red Hat has released security updates for affected NGINX packages, including version 1.26.3-1.el10_0.9 and related modules. Users should apply these official patches promptly to remediate the vulnerability. Exploitation requires specific non-default rewrite configurations; reviewing and adjusting these configurations may reduce risk. No additional mitigations are specified by the vendor advisory.
Description
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.
References
- my.f5.com/manage/s/article/K000161019 (opens in a new tab)
- depthfirst.com/nginx-rift (opens in a new tab)
- github.com/DepthFirstDisclosures/Nginx-Rift (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-42945 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2477116 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42945.json (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:17790 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:18063 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19159 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:18041 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:17791 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:17751 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:17792 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:17793 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:17752 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:17794 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:17753 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:18029 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19371 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19374 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19372 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:17417 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:22396 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:22393 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:22394 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:22390 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:22388 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:22389 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:22382 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:22383 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:20442 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:20444 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:21275 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:58981 (opens in a new tab)