CVE-2023-35945Envoy vulnerable to HTTP/2 memory leak in nghttp2 codec
Updated under an hour ago ()
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It affects envoyproxy envoy and 4 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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Envoy is a cloud-native high-performance edge/middle/service proxy. Envoy’s HTTP/2 codec may leak a header map and bookkeeping structures upon receiving `RST_STREAM` immediately followed by the `GOAWAY` frames from an upstream server. In nghttp2, cleanup of pending requests due to receipt of the `GOAWAY` frame skips de-allocation of the bookkeeping structure and pending compressed header. The error return [code path] is taken if connection is already marked for not sending more requests due to `GOAWAY` frame. The clean-up code is right after the return statement, causing memory leak. Denial of service through memory exhaustion. This vulnerability was patched in versions(s) 1.26.3, 1.25.8, 1.24.9, 1.23.11.
- CVSS
- 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-400
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Modified
- Record last updated
- Oct 14, 2026
- First seen by InfoSec Signals
- Oct 14, 2026
Affected products
envoyproxy envoy envoyproxy:envoy (from the name) | from 1.26.0, < 1.26.3; from 1.25.0, < 1.25.8; from 1.24.0, < 1.24.9; from 1.23.0, < 1.23.11 | CNA record |
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.0 before V3.1.5 | CISA ADP |
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name) | from V3.1.0 before V3.1.5 | CISA ADP |
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.0 before V3.1.5 | CISA ADP |
envoyproxy envoy envoyproxy:envoy | before 1.23.11; from 1.24.0 before 1.24.9; from 1.25.0 before 1.25.8; from 1.26.0 before 1.26.3 | NVD |
nghttp2 nghttp2 nghttp2:nghttp2 | before 1.55.1 | NVD |
References
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-jfxv-29pc-x22rx-refsource-confirm, vendor-advisory
- https://github.com/nghttp2/nghttp2/blob/e7f59406556c80904b81b593d38508591bb7523a/lib/nghttp2_session.c#L3346x-refsource-misc, product
- https://cert-portal.siemens.com/productcert/html/ssa-398330.html
- https://cert-portal.siemens.com/productcert/html/ssa-943925.html
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.