CVE Intelligence
Medium Denial of service

CVE-2026-114603 — OpenTelemetry Python: Unbounded tracestate parsing in opentelemetry-api

OpenTelemetry Python provides the Python API and SDK for OpenTelemetry. Prior to 1.45.1, the opentelemetry-api function TraceState.from_header in opentelemetry/trace/span.py, reached through TraceContextTextMapPropagator.extract, parses inbound W3C tracestate headers with an unbounded optional-whitespace regular expression. A malformed header containing a long run of spaces or tabs without a following comma causes quadratic backtracking before the member-count limit is applied. Services using the default W3C Trace Context propagator can therefore spend excessive CPU time on one unauthenticated request when the HTTP server, parser, gateway, or custom carrier accepts a sufficiently large header. The processing can occupy a synchronous worker or delay unrelated requests on the same asynchronous event loop. The impact is limited to availability and does not expose or modify telemetry data or allow code execution. This issue is fixed in version 1.45.1.

Published Oct 22, 2026 · Updated Oct 22, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: GitHub_M

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
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.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.49%
ahead of 42% of scored CVEs · Oct 27, 2026
Affects
Open-telemetry
Opentelemetry-python and 1 more
CVSS base
5.3
Medium · 3 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

  • Pip Opentelemetry-api: fixed in version 1.45.1 — github.com (GitHub Security Advisories)

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.

  1. Identify exposed assets running the affected vendor/product/version combinations (Open-telemetry Opentelemetry-python, Pip Opentelemetry-api).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. Apply the fixed version or the patch documented under Remediation.
  4. Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Open-telemetry Opentelemetry-python version < 1.45.1 Vulnerable CVE Program (cve.org) e CISA ADP
Pip Opentelemetry-api ≤ 1.45.0 Vulnerable GitHub Security Advisories

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
5.3 CVSS 3.1 Medium 3.9 1.4 security-advisories@github.com via NIST National Vulnerability Database
5.3 CVSS 3.1 Medium — — GitHub, Inc. via GitHub Security Advisories
5.3 CVSS 3.1 Medium — — GitHub_M via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L (score shown at the top: security-advisories@github.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-400 · Uncontrolled Resource Consumption

Other CVEs with this weakness →

EPSS over time FIRST

Oct 23, 2026 → Oct 27, 2026 · 5 reading(s) · max 0.49%

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).
  • Track CPU/memory spikes and availability drops correlated with request patterns.
web/proxy/WAF logsnetwork IDS/IPSresource metrics

Timeline

What happened to this CVE, newest first.

  • 2026
  • Source status changed · Received → Awaiting Analysis
    Oct 22, 2026 · NIST National Vulnerability Database
  • Fix documented
    Oct 22, 2026 · GitHub Security Advisories
  • Affected products added · pip/opentelemetry-api
    Oct 22, 2026 · GitHub Security Advisories
  • Affected products added · open-telemetry/opentelemetry-python
    Oct 22, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 22, 2026
  • CVSS changed · 5.3
    Oct 22, 2026 · NIST National Vulnerability Database
  • Source status changed · → Received
    Oct 22, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 22, 2026 · Alertas do Telegram
  • CVE published
    Oct 22, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 22, 2026 – Oct 22, 2026
  • 1× Official description updated · Oct 22, 2026 – Oct 22, 2026

References

6 on the record

Elsewhere on this site

Open-telemetry
every CVE for this vendor
Denial of service
same class
CWE-400
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-116694 OpenTelemetry Python: Unbounded memory allocation in Jaeger baggage propagation 16h

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 CISA SSVC assessment.
  • 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-2026-114603 is "OpenTelemetry Python: Unbounded tracestate parsing in opentelemetry-api", rated Medium. It affects Opentelemetry-python (Open-telemetry); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.3 describes technical severity. EPSS 0.49% 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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