CVE-2026-34451

mediumpriority · track · 22EPSS 0.003 · 28 %ileEUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.35% (28th) EPSS
CVSS 5.4 · medium
Is it mine?
3 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · nvd · osv

EPSS · scored 2026-10-27

Claude SDK for TypeScript provides access to the Claude API from server-side TypeScript or JavaScript applications. From version 0.79.0 to before version 0.81.0, the local filesystem memory tool in the Anthropic TypeScript SDK validated model-supplied paths using a string prefix check that did not append a trailing path separator. A model steered by prompt injection could supply a crafted path that resolved to a sibling directory sharing the memory root's name as a prefix, allowing reads and writes outside the sandboxed memory directory. This issue has been patched in version 0.81.0.

01

cvss

Technical severity, 0–10. One row per scoring source.

6.3
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 1.7–6.3

v3.15.4mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:Nprimary · NVD / NIST USexploitability 2.2 · impact 2.7
v3.15.4mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:Nsecondary · OSV
v4.06.3mediumCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:Nsecondary · ENISA EU
v4.06.3mediumCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/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:Xsecondary · security-advisories@github.com
v4.01.7lowCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/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:Xsecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

04

affected products (3)

Products and version ranges known to be affected.

05

advisories (1)

Vendor and ecosystem advisories describing this.

  • GHSA-5474-4w2j-mq4cClaude SDK for TypeScript: Memory Tool Path Validation Allows Sandbox Escape to Sibling Directories2026-04-01ghsa · osvUS

    The local filesystem memory tool in the Anthropic TypeScript SDK validated model-supplied paths using a string prefix check that did not append a trailing path separator. A model steered by prompt injection could supply a crafted path that resolved to a sibling directory sharing the memory root's name as a prefix, allowing reads and writes outside the sandboxed memory directory. Users on the affected versions are advised to update to the latest version. Claude SDK for TypeScript thanks [hackerone.com/nicksim](https://hackerone.com/nicksim) for reporting this issue!

06

also known as (3)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

published 2026-03-31modified 2026-07-24
08

references (11)

External citations — patches, advisories, analysis.

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