Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
CVE-2026-15709
Red Hat Red Hat Enterprise Linux 10 — Soupwebsocketextensiondeflate: libsoup: libsoup: websocket permessage-deflate unbounded decompression remote denial of service
AV AC PR UI S C I A CVSS EPSS %ile KEV
N L N N U N N H 7.5 .0088 57.8 —
AFFECTED
Product Versions Fixed
Red Hat Enterprise Linux 10 unspecified 0:3.6.5-3.el10_2.14
Red Hat Enterprise Linux 10.0 Extended Update Support unspecified 0:3.6.5-3.el10_0.17
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support unspecified 0:2.62.3-2.el8_4.10
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On unspecified 0:2.62.3-2.el8_4.10
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support unspecified 0:2.62.3-2.el8_6.10
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On unspecified 0:2.62.3-2.el8_6.10
Red Hat Enterprise Linux 8.8 Telecommunications Update Service unspecified 0:2.62.3-3.el8_8.11
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions unspecified 0:2.62.3-3.el8_8.11
Red Hat Enterprise Linux 9 unspecified 0:2.72.0-16.el9_8.3
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions unspecified 0:2.72.0-8.el9_2.13
+ 5 more
TIMELINE
Jul 14 Reserved by redhat
Jul 14 Published (CNA: redhat)
Sep 16 PATCH SHIPPED — CVE-2026-15709 (Red Hat Enterprise Linux 10). Fixed in Red Hat Enterprise Linux 10 0:3.6.5-3.el10_2.14.
Description
A flaw was found in libsoup's WebSocket implementation when using the permessage-deflate extension. The extension's decompression loop (inflate()) processes data in chunks without enforcing an upper boundary limit on the output buffer size. While libsoup limits the incoming compressed frame size via max_incoming_payload_size, it fails to track or limit memory allocation during decompression. A separate check for decompressed size (max_total_message_size) exists but executes only after inflation is complete, and it is entirely disabled by default for client connections. A remote, unauthenticated attacker can exploit this by sending a small, highly compressed payload (a decompression bomb), causing unbounded memory allocation that triggers an Out-of-Memory (OOM) crash and a Denial of Service (DoS).
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
|---|
| July 14, 2026 | Reserved | Reserved by redhat |
| July 14, 2026 | Published | Published (CNA: redhat) |
| September 16, 2026 | PATCH SHIPPED | PATCH SHIPPED — CVE-2026-15709 (Red Hat Enterprise Linux 10). Fixed in Red Hat Enterprise Linux 10 0:3.6.5-3.el10_2.14. |
Affected
Affected products and packages — 15 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — | 0:3.6.5-3.el10_2.14 |
| Red Hat | Red Hat Enterprise Linux 10.0 Extended Update Support | — | — | 0:3.6.5-3.el10_0.17 |
| Red Hat | Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | — | — | 0:2.62.3-2.el8_4.10 |
| Red Hat | Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On | — | — | 0:2.62.3-2.el8_4.10 |
| Red Hat | Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | — | — | 0:2.62.3-2.el8_6.10 |
| Red Hat | Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On | — | — | 0:2.62.3-2.el8_6.10 |
| Red Hat | Red Hat Enterprise Linux 8.8 Telecommunications Update Service | — | — | 0:2.62.3-3.el8_8.11 |
| Red Hat | Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions | — | — | 0:2.62.3-3.el8_8.11 |
| Red Hat | Red Hat Enterprise Linux 9 | — | — | 0:2.72.0-16.el9_8.3 |
| Red Hat | Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions | — | — | 0:2.72.0-8.el9_2.13 |
| Red Hat | Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions | — | — | 0:2.72.0-8.el9_4.12 |
| Red Hat | Red Hat Enterprise Linux 9.6 Extended Update Support | — | — | 0:2.72.0-10.el9_6.9 |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | — |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | — |
| Red Hat | Red Hat Enterprise Linux 8 | — | — | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-15709 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.
