---
cve: "CVE-2026-81869"
severity: "MEDIUM"
cvss: 5.1
epss: "5%"
vendor: "open-telemetry"
kev: false
exploited: false
published: "2026-09-16 21:17:22"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-18T08:42:12+02:00"
---

# CVE-2026-81869

> 5.1 MEDIUM · 🧪 PoC

## Beschreibung

OpenTelemetry-Go is the Go implementation of OpenTelemetry. From version 1.10.0 until 1.33.0, the sdk/trace/span.go attribute truncation path can fail to enforce AttributeValueLengthLimit for string and string-slice attributes containing the valid Unicode replacement character U+FFFD. safeTruncateValidUTF8 treats the valid replacement rune as invalid UTF-8 and returns the original input, while strings.ToValidUTF8 leaves that valid rune unchanged, so a second safeTruncate attempt can also return the oversized value. An attacker who controls span attribute content can retain values longer than the configured limit, increasing per-span memory use and weakening denial-of-service protection in the instrumented process. This issue is fixed in version 1.33.0.

## CVSS-Vektor

```
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 8c38f80ec37ca5f5ef037c6b19997764926ba049 (Commit)

## Referenzen

- <https://github.com/open-telemetry/opentelemetry-go/security/advisories/GHSA-p9f8-wvj8-2fg8>
- <https://github.com/open-telemetry/opentelemetry-go/issues/5996>
- <https://github.com/open-telemetry/opentelemetry-go/pull/5997>
- <https://github.com/open-telemetry/opentelemetry-go/commit/e016a78c9f5b24a1c2beeaad47686c2f2213f49a>
- <https://github.com/open-telemetry/opentelemetry-go/releases/tag/sdk/v1.33.0>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-81869) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_