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TI-2026-79469 Aliases CVE-2026-115384GHSA-6fff-wrjr-wjxr

Stack buffer overflow in Wasmtime async callbacks

Priority MEDIUM 42CWE-20Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

Wasmtime from 39.0.0 before 48.0.4 and from 49.0.0 before 49.0.2 contains a stack buffer overflow. Improper input validation of async callback result types lets a malicious guest write about 16KB to the native stack. An attacker who supplies a component with mistyped component-model-async callback functions can overwrite return addresses, crashing the host or escaping the sandbox.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write ~16KB to the native stack via unvalidated async callback result types. Attackers can supply components with mistyped component-model-async callback functions to overwrite return addresses, crashing the host or escaping the sandbox.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00312 24th percentileScored 2026-11-07
Fix Fixed wasmtime (bytecodealliance): 48.0.4, 49.0.2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
bytecodealliancewasmtime39.0.0 to before 48.0.4; 49.0.0 to before 49.0.248.0.4, 49.0.2Patch availableCNA
  • wasmtime Vendorbytecodealliance Affected 39.0.0 to before 48.0.4; 49.0.0 to before 49.0.2 Fixed in 48.0.4, 49.0.2 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:*:*:*——bytecodealliance
  • cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:*:*:* Versions — — ·bytecodealliance

Remediation

Upgrade Wasmtime to 48.0.4 or 49.0.2. The sources list no fixed version for Wasmtime outside these branches.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

  • Fix · CNA wasmtime (bytecodealliance) Fixed in 48.0.4, 49.0.2

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    bytecodealliance wasmtime 48.0.4, 49.0.2

    5 records Highest priority Priority MEDIUM 1 MEDIUM, 4 LOW

    Other records, highest priority first

    • TI-2026-79464 Missing GC rooting in Wasmtime try_call corrupts GC heapPriority LOW 30
    • TI-2026-79470 Host panic in Wasmtime WASIp3 timestamp handlingPriority LOW 29
    • TI-2026-79468 Wasmtime tag import validation flaw corrupts GC heapPriority LOW 26
    Show all 5 records →

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

Not affected: 2 products
  • Red Hat Connectivity Link 1
  • Red Hat Enterprise Linux 10

Timeline

  1. 2026-10-22 Threatist record created from CVE-2026-115384
  2. 2026-10-22 Alias added: GHSA-6fff-wrjr-wjxr
  3. 2026-10-29 Affected versions changed · Red Hat
  4. 2026-10-29 CVSS score added · Red Hat
  5. 2026-10-29 CISA SSVC decision points changed

References

Advisory 1

  • TI-2026-85541 WAMR fast interpreter loader heap overflow via constant deduplication mismatch CVSS 4.0HIGH 8.8
  • TI-2024-16741 An issue in bytecodealliance wasm-micro-runtime before v.b3f728c and fixed in commit… CVSS 3.1HIGH 8.8
  • TI-2024-22658 An out-of-bound memory read vulnerability was discovered in Bytecode Alliance… CVSS 3.1HIGH 7.5
  • TI-2024-18300 wasm-micro-runtime (aka WebAssembly Micro Runtime or WAMR) 06df58f is vulnerable to NULL… CVSS 3.1HIGH 7.5
  • TI-2023-26034 An heap overflow vulnerability was discovered in Bytecode alliance wasm-micro-runtime… CVSS 3.1HIGH 7.5
  • TI-2025-33969 WebAssembly Micro Runtime's `--addr-pool` option allows all IPv4 addresses when subnet mask is not specified CVSS 4.0MEDIUM 6.9
See all 97 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences