Soupwebsocketextensiondeflate: libsoup: libsoup: websocket permessage-deflate unbounded…
Priority HIGH 72CWE-409Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 20 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
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).
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00883 59th percentileScored 2026-11-07
Fix Partial Red Hat: 9 advisoriesRed Hat: 20 fixed, 3 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | 3.6.5-3.el10_2.14 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 10.0 Extended Update Support | — | 3.6.5-3.el10_0.17 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | — | 2.62.3-2.el8_4.10 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On | — | 2.62.3-2.el8_4.10 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | — | 2.62.3-2.el8_6.10 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On | — | 2.62.3-2.el8_6.10 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.8 Telecommunications Update Service | — | 2.62.3-3.el8_8.11 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions | — | 2.62.3-3.el8_8.11 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | 2.72.0-16.el9_8.3 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions | — | 2.72.0-8.el9_2.13 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions | — | 2.72.0-8.el9_4.12 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9.6 Extended Update Support | — | 2.72.0-10.el9_6.9 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | — | No fix listed | CNA |
- Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in 3.6.5-3.el10_2.14 Patch available CNA
- Red Hat Enterprise Linux 10.0 Extended Update Support VendorRed Hat Affected — Fixed in 3.6.5-3.el10_0.17 Patch available CNA
- Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support VendorRed Hat Affected — Fixed in 2.62.3-2.el8_4.10 Patch available CNA
- Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On VendorRed Hat Affected — Fixed in 2.62.3-2.el8_4.10 Patch available CNA
- Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support VendorRed Hat Affected — Fixed in 2.62.3-2.el8_6.10 Patch available CNA
- Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On VendorRed Hat Affected — Fixed in 2.62.3-2.el8_6.10 Patch available CNA
- Red Hat Enterprise Linux 8.8 Telecommunications Update Service VendorRed Hat Affected — Fixed in 2.62.3-3.el8_8.11 Patch available CNA
- Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions VendorRed Hat Affected — Fixed in 2.62.3-3.el8_8.11 Patch available CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in 2.72.0-16.el9_8.3 Patch available CNA
- Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions VendorRed Hat Affected — Fixed in 2.72.0-8.el9_2.13 Patch available CNA
- Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions VendorRed Hat Affected — Fixed in 2.72.0-8.el9_4.12 Patch available CNA
- Red Hat Enterprise Linux 9.6 Extended Update Support VendorRed Hat Affected — Fixed in 2.72.0-10.el9_6.9 Patch available CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in — No fix listed CNA
CPE names CNA · 21
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:/o:redhat:enterprise_linux:10.2 | 10.2 | — | Red Hat |
| cpe:/o:redhat:enterprise_linux_eus:10.0 | 10.0 | — | Red Hat |
| cpe:/a:redhat:rhel_aus:8.4::appstream | 8.4 | — | Red Hat |
| cpe:/a:redhat:rhel_eus_long_life:8.4::appstream | 8.4 | — | Red Hat |
| cpe:/o:redhat:rhel_aus:8.4::baseos | 8.4 | — | Red Hat |
| cpe:/o:redhat:rhel_eus_long_life:8.4::baseos | 8.4 | — | Red Hat |
| cpe:/a:redhat:rhel_aus:8.6::appstream | 8.6 | — | Red Hat |
| cpe:/a:redhat:rhel_eus_long_life:8.6::appstream | 8.6 | — | Red Hat |
| cpe:/o:redhat:rhel_aus:8.6::baseos | 8.6 | — | Red Hat |
| cpe:/o:redhat:rhel_eus_long_life:8.6::baseos | 8.6 | — | Red Hat |
- cpe:/o:redhat:enterprise_linux:10.2 Versions 10.2 — ·Red Hat
- cpe:/o:redhat:enterprise_linux_eus:10.0 Versions 10.0 — ·Red Hat
- cpe:/a:redhat:rhel_aus:8.4::appstream Versions 8.4 — ·Red Hat
- cpe:/a:redhat:rhel_eus_long_life:8.4::appstream Versions 8.4 — ·Red Hat
- cpe:/o:redhat:rhel_aus:8.4::baseos Versions 8.4 — ·Red Hat
- cpe:/o:redhat:rhel_eus_long_life:8.4::baseos Versions 8.4 — ·Red Hat
- cpe:/a:redhat:rhel_aus:8.6::appstream Versions 8.6 — ·Red Hat
- cpe:/a:redhat:rhel_eus_long_life:8.6::appstream Versions 8.6 — ·Red Hat
- cpe:/o:redhat:rhel_aus:8.6::baseos Versions 8.6 — ·Red Hat
- cpe:/o:redhat:rhel_eus_long_life:8.6::baseos Versions 8.6 — ·Red Hat
Show 11 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:/a:redhat:rhel_e4s:8.8::appstream | 8.8 | — | Red Hat |
| cpe:/a:redhat:rhel_tus:8.8::appstream | 8.8 | — | Red Hat |
| cpe:/o:redhat:rhel_e4s:8.8::baseos | 8.8 | — | Red Hat |
| cpe:/o:redhat:rhel_tus:8.8::baseos | 8.8 | — | Red Hat |
| cpe:/a:redhat:enterprise_linux:9::appstream | 9 | — | Red Hat |
| cpe:/a:redhat:rhel_e4s:9.2::appstream | 9.2 | — | Red Hat |
| cpe:/a:redhat:rhel_e4s:9.4::appstream | 9.4 | — | Red Hat |
| cpe:/a:redhat:rhel_eus:9.6::appstream | 9.6 | — | Red Hat |
| cpe:/o:redhat:rhel_els:6 | 6 | — | Red Hat |
| cpe:/o:redhat:rhel_els:7 | 7 | — | Red Hat |
| cpe:/a:redhat:enterprise_linux:8 | 8 | — | Red Hat |
- cpe:/a:redhat:rhel_e4s:8.8::appstream Versions 8.8 — ·Red Hat
- cpe:/a:redhat:rhel_tus:8.8::appstream Versions 8.8 — ·Red Hat
- cpe:/o:redhat:rhel_e4s:8.8::baseos Versions 8.8 — ·Red Hat
- cpe:/o:redhat:rhel_tus:8.8::baseos Versions 8.8 — ·Red Hat
- cpe:/a:redhat:enterprise_linux:9::appstream Versions 9 — ·Red Hat
- cpe:/a:redhat:rhel_e4s:9.2::appstream Versions 9.2 — ·Red Hat
- cpe:/a:redhat:rhel_e4s:9.4::appstream Versions 9.4 — ·Red Hat
- cpe:/a:redhat:rhel_eus:9.6::appstream Versions 9.6 — ·Red Hat
- cpe:/o:redhat:rhel_els:6 Versions 6 — ·Red Hat
- cpe:/o:redhat:rhel_els:7 Versions 7 — ·Red Hat
- cpe:/a:redhat:enterprise_linux:8 Versions 8 — ·Red Hat
Remediation
Red Hat 9 advisories
- RHSA-2026:71389 Released 2026-09-24 · Red Hat rating Moderatelibsoup3 security update
- Red Hat Enterprise Linux AppStream EUS (v. 10.0) libsoup3-3.6.5-3.el10_0.17, libsoup3-devel-3.6.5-3.el10_0.17
- Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) libsoup3-doc-3.6.5-3.el10_0.17
- RHSA-2026:70598 Released 2026-09-23 · Red Hat rating Moderatelibsoup security update
- Red Hat Enterprise Linux AppStream AUS (v.8.6) libsoup-devel-2.62.3-2.el8_6.10
- Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) libsoup-devel-2.62.3-2.el8_6.10
- Red Hat Enterprise Linux BaseOS AUS (v.8.6) libsoup-2.62.3-2.el8_6.10
- Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) libsoup-2.62.3-2.el8_6.10
- RHSA-2026:70599 Released 2026-09-23 · Red Hat rating Moderatelibsoup security update
- Red Hat Enterprise Linux AppStream AUS (v.8.4) libsoup-devel-2.62.3-2.el8_4.10
- Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) libsoup-devel-2.62.3-2.el8_4.10
- Red Hat Enterprise Linux BaseOS AUS (v.8.4) libsoup-2.62.3-2.el8_4.10
- Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) libsoup-2.62.3-2.el8_4.10
Show 6 more Red Hat advisories
- RHSA-2026:69863 Released 2026-09-22 · Red Hat rating Moderatelibsoup security update
- Red Hat Enterprise Linux AppStream E4S (v.8.8) libsoup-devel-2.62.3-3.el8_8.11
- Red Hat Enterprise Linux AppStream TUS (v.8.8) libsoup-devel-2.62.3-3.el8_8.11
- Red Hat Enterprise Linux BaseOS E4S (v.8.8) libsoup-2.62.3-3.el8_8.11
- Red Hat Enterprise Linux BaseOS TUS (v.8.8) libsoup-2.62.3-3.el8_8.11
- RHSA-2026:69297 Released 2026-09-21 · Red Hat rating Moderatelibsoup security update
- Red Hat Enterprise Linux AppStream E4S (v.9.2) libsoup-2.72.0-8.el9_2.13, libsoup-devel-2.72.0-8.el9_2.13
- RHSA-2026:69108 Released 2026-09-21 · Red Hat rating Moderatelibsoup security update
- Red Hat Enterprise Linux AppStream E4S (v.9.4) libsoup-2.72.0-8.el9_4.12, libsoup-devel-2.72.0-8.el9_4.12
- RHSA-2026:68612 Released 2026-09-17 · Red Hat rating Moderatelibsoup security update
- Red Hat Enterprise Linux AppStream EUS (v.9.6) libsoup-2.72.0-10.el9_6.9, libsoup-devel-2.72.0-10.el9_6.9
- RHSA-2026:68234 Released 2026-09-16 · Red Hat rating Moderatelibsoup security update
- Red Hat Enterprise Linux AppStream (v. 9) libsoup-2.72.0-16.el9_8.3, libsoup-devel-2.72.0-16.el9_8.3
- RHSA-2026:68235 Released 2026-09-16 · Red Hat rating Importantlibsoup3 security update
- Red Hat Enterprise Linux AppStream (v. 10) libsoup3-3.6.5-3.el10_2.14, libsoup3-devel-3.6.5-3.el10_2.14
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libsoup3-doc-3.6.5-3.el10_2.14
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support and 13 more products — RHSA-2026:68234
2 records Highest priority Priority HIGH 2 HIGH
Other records, highest priority first
- TI-2026-13220 Resource allocation without limits in Red Hat Enterprise Linux 10Priority HIGH 72
- Advisory ·
Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support and 13 more products — RHSA-2026:68612
2 records Highest priority Priority HIGH 2 HIGH
Other records, highest priority first
- TI-2026-13220 Resource allocation without limits in Red Hat Enterprise Linux 10Priority HIGH 72
Show 6 more groups
- Advisory ·
Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support and 13 more products — RHSA-2026:69108
2 records Highest priority Priority HIGH 2 HIGH
Other records, highest priority first
- TI-2026-13220 Resource allocation without limits in Red Hat Enterprise Linux 10Priority HIGH 72
- Advisory ·
Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support and 13 more products — RHSA-2026:69297
2 records Highest priority Priority HIGH 2 HIGH
Other records, highest priority first
- TI-2026-13220 Resource allocation without limits in Red Hat Enterprise Linux 10Priority HIGH 72
- Advisory ·
Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support and 13 more products — RHSA-2026:69863
2 records Highest priority Priority HIGH 2 HIGH
Other records, highest priority first
- TI-2026-13220 Resource allocation without limits in Red Hat Enterprise Linux 10Priority HIGH 72
- Advisory ·
Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support and 13 more products — RHSA-2026:70598
2 records Highest priority Priority HIGH 2 HIGH
Other records, highest priority first
- TI-2026-13220 Resource allocation without limits in Red Hat Enterprise Linux 10Priority HIGH 72
- Advisory ·
Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support and 13 more products — RHSA-2026:70599
2 records Highest priority Priority HIGH 2 HIGH
Other records, highest priority first
- TI-2026-13220 Resource allocation without limits in Red Hat Enterprise Linux 10Priority HIGH 72
- Advisory ·
Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support and 13 more products — RHSA-2026:71389
2 records Highest priority Priority HIGH 2 HIGH
Other records, highest priority first
- TI-2026-13220 Resource allocation without limits in Red Hat Enterprise Linux 10Priority HIGH 72
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:68235 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:68234 |
| Red Hat Enterprise Linux AppStream AUS (v.8.4) | Fixed | RHSA-2026:70599 |
| Red Hat Enterprise Linux AppStream AUS (v.8.6) | Fixed | RHSA-2026:70598 |
| Red Hat Enterprise Linux AppStream E4S (v.8.8) | Fixed | RHSA-2026:69863 |
| Red Hat Enterprise Linux AppStream E4S (v.9.2) | Fixed | RHSA-2026:69297 |
| Red Hat Enterprise Linux AppStream E4S (v.9.4) | Fixed | RHSA-2026:69108 |
| Red Hat Enterprise Linux AppStream EUS (v. 10.0) | Fixed | RHSA-2026:71389 |
| Red Hat Enterprise Linux AppStream EUS (v.9.6) | Fixed | RHSA-2026:68612 |
| Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) | Fixed | RHSA-2026:70599 |
| Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) | Fixed | RHSA-2026:70598 |
| Red Hat Enterprise Linux AppStream TUS (v.8.8) | Fixed | RHSA-2026:69863 |
| Red Hat Enterprise Linux BaseOS AUS (v.8.4) | Fixed | RHSA-2026:70599 |
| Red Hat Enterprise Linux BaseOS AUS (v.8.6) | Fixed | RHSA-2026:70598 |
| Red Hat Enterprise Linux BaseOS E4S (v.8.8) | Fixed | RHSA-2026:69863 |
| Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) | Fixed | RHSA-2026:70599 |
| Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) | Fixed | RHSA-2026:70598 |
| Red Hat Enterprise Linux BaseOS TUS (v.8.8) | Fixed | RHSA-2026:69863 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:68235 |
| Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) | Fixed | RHSA-2026:71389 |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-15709
- 2026-10-03 Alias added: GHSA-gv2g-7h3v-q5f3
References
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Sources
- CVE-2026-15709 · CVE Program
- CVE-2026-15709 · NVD
- FIRST EPSS
- GHSA-gv2g-7h3v-q5f3 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-15709 · Red Hat security data · CC BY 4.0
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