CVE-2026-107291 — Pydantic AI OpenTelemetry instrumentation: exception events on tool and agent run spans include content when `include_content=False`
Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 0.3.4 until 1.107.6 and 2.44.0, OpenTelemetry instrumentation configured with InstrumentationSettings(include_content=False) can still export sensitive agent content through exception.message and exception.stacktrace events, error status descriptions, and model_request_parameters containing instructions or the prompted_output_template. The exposed data is available to readers of the configured telemetry backend and can include tool feedback, provider error bodies, runtime instructions, and structured-output templates even though message attributes are redacted. This issue does not grant new access to agent data, and deployments that do not use include_content=False are not affected by the setting bypass. This issue is fixed in versions 1.107.6 and 2.44.0.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.5% (30-day exploitation probability)+6
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented mitigation — github.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Pydantic Pydantic Ai, Pydantic Pydantic-ai-slim).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Pydantic | Pydantic Ai | ≥ 0.3.4 and < 1.107.4≥ 2.0.0 and < 2.44.0 | Vulnerable | NIST National Vulnerability Database |
| Pydantic | Pydantic Ai | version >= 0.3.4, < 1.107.6version >= 2.0.0b1, < 2.44.0 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Pydantic | Pydantic-ai-slim | version >= 0.3.4, < 1.107.6version >= 2.0.0b1, < 2.44.0 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 2.3 | CVSS 4.0 | Low | — | — | security-advisories@github.com via NIST National Vulnerability Database |
| 2.3 | CVSS 4.0 | Low | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
| 4.3 | CVSS 3.1 | Medium | 2.8 | 1.4 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.52%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · pydantic/pydantic-ai, pydantic/pydantic-ai-slim
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 4.3
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
13 on the record
- github.com/pydantic/pydantic-ai/security/advisories/GHSA-4x9p-g9wm-8q7f
- github.com/pydantic/pydantic-ai/pull/8408
- github.com/pydantic/pydantic-ai/commit/6b14c74cb281f899a2ae4fae5327111e33f60771
- github.com/pydantic/pydantic-ai/commit/4e013c51a50659aba2adf7853bfb22bb77f6a518
- github.com/pydantic/pydantic-ai/commit/de4e61515327bd80a19cd8552001c30933e6acc3
- github.com/pydantic/pydantic-ai/pull/8403
- github.com/pydantic/pydantic-ai/pull/8428
- github.com/pydantic/pydantic-ai/releases/tag/v2.44.0
- github.com/pydantic/pydantic-ai/releases/tag/v1.107.6
- github.com/pydantic/pydantic-ai/commit/963dec5f70d6f558997fc259356c0090cc5ea487
- github.com/pydantic/pydantic-ai/pull/8404
- github.com/pydantic/pydantic-ai/pull/8429
- github.com/pydantic/pydantic-ai/commit/7ee27e38ab2e525ca60ff1a25d16413ff989fd79
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-107295 `pydantic-ai-slim` web UI `/api/chat` accepts browser-simple cross-origin requests that can trigger agent tool execution 7d
- Medium CVE-2026-107294 Pydantic AI: Unbounded memory use when downloading remote content via web_fetch or FileUrl 7d
- Medium CVE-2026-107290 Pydantic AI: Event loop blocked by quadratic title extraction in `web_fetch` 7d
- Medium CVE-2026-107292 Pydantic AI Web chat UI (`Agent.to_web()`, `clai web`): the local chat endpoint does not validate the `Host` header 7d
- Medium CVE-2026-107293 Pydantic AI OpenTelemetry instrumentation: retry prompt content is not redacted when `include_content=False` 7d
- Medium CVE-2026-107289 Pydantic AI: SSRF cloud-metadata blocklist bypass via IPv6 zone identifier (incomplete fix for CVE-2026-46678 and CVE-2026-48782) 7d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-107291 is "Pydantic AI OpenTelemetry instrumentation: exception events on tool and agent run spans include content when `include_content=False`", rated Medium. It affects Pydantic Ai (Pydantic); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 4.3 describes technical severity. EPSS 0.52% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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