temporalio/tchannel-go malformed checksum type causes process termination
Published Sep 21, 2026
8.7
HIGHCVSS 4.0
EPSS 0.71%
Description
github.com/temporalio/tchannel-go did not validate the one-byte checksum-type field in inbound TChannel call frames. A network peer that can reach a listener can complete the standard initialization handshake and send a call request with an unsupported checksum type. The parser uses that value as an index into a four-entry checksum pool, causing an unrecovered Go panic on the connection read goroutine and terminating the hosting process. This allows remote denial of service against applications that expose the listener to untrusted peers. The impact is limited to availability; no confidentiality or integrity impact was identified.
Affected products
-
- Version 0.0.0-20160105034737-a6904155f628StatusaffectedConstraints<1.22.1-0.20260720194454-0cb017f6870a
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Temporal Technologies, Inc. | Temporalio/tchannel-GO | unaffected |
|
No data.
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
Vendor solution
Upgrade github.com/temporalio/tchannel-go to v1.22.1 or later. The fix rejects unsupported checksum types during direct and relay frame parsing and prevents out-of-range checksum-pool access.
Metrics
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
No CVSS v3.1 score for this CVE.
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
YesTechnical Impact
PartialDecision
n/aAssessed Sep 21, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 3, 2026.
Score over time
Sep–Oct 2026- EPSS v5
Percentile over time
- EPSS v5
Table of values (2 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 3, 2026 | 0.71% (0.00710) | 51.88th | v5 (v2026.06.15) |
| Sep 22, 2026 | 0.52% (0.00520) | 43.17th | v5 (v2026.06.15) |
References (6)
- https://github.com/temporalio/tchannel-go/blob/8706a1ab5f617efd79dace7ab2d1d80cc1881df0/checksum.go#L29-L93 product
- https://github.com/temporalio/tchannel-go/blob/8706a1ab5f617efd79dace7ab2d1d80cc1881df0/reqres.go#L280-L295 product
- https://github.com/temporalio/tchannel-go/commit/0cb017f6870a8420695abeb9a4560d39dadc4e2e patch
- https://github.com/temporalio/tchannel-go/commit/a6904155f628b9e602b7bc88ef489004a786f7f4 product
- https://github.com/temporalio/tchannel-go/pull/14 patch
- https://github.com/temporalio/tchannel-go/tree/v1.22.1 product
Change history (0)
No recorded changes yet.