Releases

This is a routine patch release for OpenCost, dominated by bug fixes for GPU pricing, data races, and Azure Windows pricing, plus a new STACKIT provider integration. There are no breaking changes, deprecations, or CVE fixes in this release.

Fluentd v1.19.3 is a security and hardening patch: it tightens validation in out_http (host checks) and output (tag path boundaries), enforces size limits on decompressed payloads in buffer and in_http, and restricts default access and visibility for in_monitor_agent and in_debug_agent. Bug fixes address storage, parsing, and connection reuse issues.

• breakingout_http: strict host validation for dynamic endpoints

  Host validation for dynamic endpoints in out_http is now strictly enforced in v1.19.3. Configuration that supplies hostnames to out_http at runtime must now conform to stricter validation rules.

• breakingbuffer, in_http: decompressed payload size limits

  Decompressed payload sizes are now limited in buffer and in_http as of v1.19.3. Requests or buffered data that decompress beyond the enforced limit will be rejected.

• breakingin_monitor_agent: sensitive info visibility restricted by default

  in_monitor_agent changes default visibility of config, retry, and debug info in v1.19.3. Sensitive information previously exposed by default is now hidden unless explicitly enabled.

• breakingoutput: strict tag path boundary validation

  Output tag path boundaries are now strictly validated in v1.19.3. Tag paths that do not conform to the enforced boundary rules will be rejected.

• breakingin_debug_agent: local-only access by default

  in_debug_agent accepts connections only from the local machine by default in v1.19.3. Remote connections to the debug agent will be rejected unless the bind address is explicitly changed.

v0.155.0 is a breaking-change release for operators: seven stabilized feature gates are removed, memory_limiter metrics get a new prefix, and two config/service APIs are deprecated in favor of snapshot-based replacements. The rest is tooling work on mdatagen and the newly relocated schemagen CLI.

• breakingSeven stabilized feature gates removed

  Applies to any collector build referencing confighttp.framedSnappy, configoptional.AddEnabledField, confmap.newExpandedValueSanitizer, exporter.PersistRequestContext, otelcol.printInitialConfig, telemetry.UseLocalHostAsDefaultMetricsAddress, or pdata.enableRefCounting via --feature-gates flags or config. These gates are gone in v0.155.0; startup will fail if they're still referenced. Drop them from your CLI args and config before upgrading.

• breakingmemory_limiter metrics renamed with processor prefix

  Applies to anyone scraping or alerting on otelcol_processor_* metrics from the memory_limiter processor. They're renamed to otelcol_processor_memory_limiter_* to disambiguate from other processors. Update dashboards, alert rules, and metric queries to the new names.

• breakingmdatagen reaggregation_enabled setting removed

  Applies to custom components using mdatagen metadata.yaml with reaggregation_enabled. The setting is removed; per-metric reaggregation config is now always generated. Old files with the field are still accepted but the value is ignored, so check generated output matches expectations.

• breakingConfig watcher APIs deprecated for snapshot-based equivalents

  Applies to extension or core code using service.Settings.CollectorConf or extensioncapabilities.ConfigWatcher. Both are deprecated in favor of service.Settings.ConfigSnapshot and extensioncapabilities.ConfigSnapshotWatcher. No forced migration yet, but plan to move to the snapshot-based APIs.

Prometheus v3.5.4 is a security-focused patch: fixes a secret-exposure bug in STACKIT SD and bumps several Go/UI dependencies to patch known CVEs. Upgrade promptly.

• securityRotate STACKIT SD credentials if you use that SD

  The /-/config endpoint was exposing STACKIT service discovery secrets in plaintext. If your Prometheus instance uses STACKIT SD and /-/config was reachable by anyone other than admins, assume those credentials are compromised and rotate them. Upgrade to v3.5.4 immediately, then restrict access to /-/config behind authentication.

• securityUpgrade to patch three Go CVEs in golang.org/x/net and OpenTelemetry

  GO-2026-5026, GO-2026-4918, and GO-2026-4985 are addressed by bumping golang.org/x/net to v0.55.0 and OpenTelemetry to v1.43.0. If you run Prometheus exposed to untrusted network traffic, this upgrade should not wait for your next maintenance window.

• enhancementghcr.io image publishing available as an alternative pull source

  Prometheus images are now also on ghcr.io. If your environment has rate-limit or access issues with Docker Hub, you can switch your image pull source to ghcr.io/prometheus/prometheus without waiting for a feature release.

Chaos Mesh v2.8.3 is a security-focused patch: critical/high CVEs addressed via Go 1.25.11 and containerd 1.7.32 upgrades, plus a NetworkChaos recovery bug fix.

• securityUpgrade to v2.8.3 to patch critical/high CVEs

  The Go toolchain and containerd in the container images had critical/high CVEs. If you're running Chaos Mesh on release-2.8, upgrade to v2.8.3 now. No config changes needed — this is a drop-in image update.

• breakingVerify NetworkChaos experiments involving crash-looping pods

  NetworkChaos recovery previously failed when the target container was in CrashLoopBackOff. v2.8.3 fixes this by falling back to the pause container's PID. If your test environments include intentionally crash-looping workloads, re-run those experiments to confirm recovery behaves correctly after the upgrade.

OTel Collector v0.154.0 fixes a startup crash in exporterhelper and changes --skip-get-modules behavior. Two minor enhancements add TLS and CORS config options.

• securityinclude_insecure_cipher_suites is opt-in — keep it that way

  The new configtls option lets you re-enable weak cipher suites, but they stay disabled by default. Do not set include_insecure_cipher_suites: true in production unless you're forced to by a legacy peer — and if you are, treat it as a temporary workaround and track it.

• breakingCheck custom build pipelines using --skip-get-modules

  If your OCB-based build scripts pass --skip-get-modules expecting go.mod to be regenerated as a side effect, that no longer happens. Audit any CI pipelines that relied on this implicit behavior and add an explicit go mod tidy step if needed.

• enhancementUpgrade if you use sending_queue with sizer enabled

  The nil-pointer panic fix in exporterhelper is critical for anyone who sets sending_queue.sizer alongside batch.enabled: false. If your collector was crashing on startup in this config, v0.154.0 resolves it — upgrade directly.

v1.21.1 is a security-focused patch release addressing findings from a formal security audit, including XSS, gzip bomb, and memory amplification vulnerabilities — upgrade immediately.

• securityUpgrade immediately — multiple audit findings patched

  This release backports fixes from a formal security audit (V01–V07). The vulnerabilities include a stored XSS on status pages, a gzip bomb in the OTLP ingestion path, memory amplification via malformed native histogram payloads, and gossip port exposure to flood/OOM attacks. These are not theoretical — they are exploitable by any client that can reach your Cortex endpoints. Upgrade to v1.21.1 now. After upgrading, review your -distributor.otlp-max-recv-msg-size setting; the default may be too permissive depending on your ingest volume.

• securityAudit your /config endpoint exposure

  Prior to this release, Swift, etcd, Redis, and HTTP basic-auth credentials were exposed in plaintext on the /config endpoint. If that endpoint was accessible to internal users or scraping systems, treat those credentials as compromised and rotate them. Going forward, restrict /config access via network policy or auth middleware regardless of masking.

• enhancementHarden memberlist gossip with new bounding flags

  Three new flags (-memberlist.packet-read-timeout, -memberlist.max-packet-size, -memberlist.max-concurrent-connections) cap inbound gossip TCP behavior. The defaults are reasonable, but if your Cortex cluster is exposed to less-trusted network segments or you've seen gossip-related OOM events, tune these explicitly. Add them to your Helm values or config management before the next planned maintenance window.

v2.19.0 ships the new /api/v3/trace-summaries endpoint and migrates the UI search to use it, plus TLS for ClickHouse and a configurable gRPC max message size.

• breakingUI search migration to /api/v3/trace-summaries requires compatible backend

  The UI now exclusively uses /api/v3/trace-summaries for search results. If you run a custom or older storage backend via the gRPC storage plugin, it must implement the SummaryReader interface or the fallback full-trace aggregation path kicks in. Verify your storage plugin supports this before upgrading. If you pin the UI separately from the backend, do not upgrade the UI to this version without also upgrading the backend to v2.19.0.

• breakingRename query.num_traces to query.search_depth in any API v3 clients

  Any scripts, dashboards, or integrations that pass query.num_traces to the v3 API will still work via the deprecated alias, but you should migrate to query.search_depth now. The deprecated alias will eventually be removed. Also check for snake_case HTTP query params — camelCase is now the canonical form, with snake_case kept as deprecated aliases.

• enhancementSet max_recv_msg_size_mib if you see gRPC message size errors in remote storage

  Teams using the gRPC remote storage plugin with large traces often hit the default gRPC message size cap. The new max_recv_msg_size_mib config option on the gRPC storage client lets you raise this limit explicitly. If you've been seeing 'received message larger than max' errors from your storage backend, configure this value in your Jaeger deployment config to fix it without workarounds.

• enhancementEnable TLS for ClickHouse storage in production

  The ClickHouse storage plugin now supports TLS configuration. If you're running ClickHouse as a Jaeger backend in any environment where the connection crosses a network boundary, configure TLS now rather than relying on network-level controls alone.