CVE-2026-108126
What it is
temporal-proxy 0.2.0 through 0.8.0 does not bind encrypted payloads to the namespace they were encrypted for. When payload encryption is enabled, the proxy chooses the decryption key by an identifier stored in the payload rather than by the namespace of the request, and nothing in the ciphertext records that namespace. A caller whom the proxy authorizes only for namespace B, and who has obtained an encrypted payload from namespace A, can therefore have the proxy decrypt it. In 0.8.0, the caller can submit the payload to the codec server's /decode endpoint. In every affected version, a caller who can also write to namespace B on the Temporal server directly can place the payload there and read it back through the proxy. This holds whether namespaces share the default key or each has its own, because a single proxy holds every key it is configured with. The issue does not give the attacker encrypted payloads they could not already obtain, and does not allow encrypted payloads to be modified.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account. High risk of data exposure.
- Exploit odds
- 0.4% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- ReservedThe CVE id was reserved by its CNA
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.4% in the next 30 days (EPSS).
- Severity: 6.0 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.4% · EPSS, next 30 days
- Weakness
- CWE-639 · Insecure direct object reference
- Record status
- Awaiting Analysis
Attack profile CVSS 4.0 · 6.0
- Attack vector
- Network
- Complexity
- Low
- Attack requirements
- Present
- Privileges needed
- Low
- User interaction
- None
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Raw vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-108126.md and follow it. Check whether this project is affected by CVE-2026-108126. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/temporalio/temporal-proxy/commit/508991c298b9ac31915dd7349ffa88d79fad3475
- https://github.com/temporalio/temporal-proxy/commit/6843a2c4626aa2c7f00fbf54e4e9fa98f6254f07
- https://github.com/temporalio/temporal-proxy/pull/221
- https://github.com/temporalio/temporal-proxy/pull/222
- https://github.com/temporalio/temporal-proxy/releases/tag/v0.9.0
References
- https://github.com/temporalio/temporal-proxy/blob/v0.8.0/pkg/crypto/dek.go#L54-L67
- https://github.com/temporalio/temporal-proxy/blob/v0.8.0/pkg/crypto/kek.go#L172-L180
- https://github.com/temporalio/temporal-proxy/blob/v0.8.0/pkg/crypto/vault.go#L256
- https://github.com/temporalio/temporal-proxy/commit/508991c298b9ac31915dd7349ffa88d79fad3475
- https://github.com/temporalio/temporal-proxy/commit/6843a2c4626aa2c7f00fbf54e4e9fa98f6254f07
- https://github.com/temporalio/temporal-proxy/discussions/146
- https://github.com/temporalio/temporal-proxy/pull/221
- https://github.com/temporalio/temporal-proxy/pull/222
- https://github.com/temporalio/temporal-proxy/releases/tag/v0.9.0