Summarize CVE-2026-45242

Exploitation requires (1) network reachability to the summarize daemon's /v1/summarize HTTP endpoint, (2) valid authentication to that endpoint at low privilege (CVSS PR:L), and (3) a vulnerable version prior to 0.15.1 of @steipete/summarize. The specific feature involved is the daemon's slide-extraction handler accepting the slidesDir request parameter without validating that it resolves within an allowed base directory. Limiting factors: the daemon must be running and reachable (developer-tool deployments often bind to localhost), the caller must already hold daemon credentials, and the file-write primitive is constrained to slide_*.png and slides.json filenames, so weaponization for code execution depends on whether those filenames can land in a location where the host or another service will read or execute them.

The CVSS 4.0 vector AV:N/AC:L/AT:N/PR:L/UI:N with VC:N/VI:H/VA:L is internally consistent with the described primitive: a low-privileged authenticated caller can reach the network-exposed daemon, integrity impact is high (arbitrary file write/delete of attacker-named slide artifacts), confidentiality impact is none, and availability impact is low (limited to deletable files matching the slide naming pattern). The 7.1 base score is meaningful but tempered by the PR:L requirement - exploitation presupposes a caller already authorized to talk to the daemon, which for a developer-oriented summarization tool is typically a local user or someone with daemon credentials, not an internet-wide unauthenticated attacker. No EPSS score, KEV listing, or POC was provided in the intelligence package, so exploitation likelihood signals are absent; the vulnerability was reported by VulnCheck (a credible source) but no evidence of in-the-wild use is available. Real-world risk skews toward targeted abuse in multi-tenant or shared-daemon deployments rather than mass exploitation.

An attacker with valid low-privileged credentials to the summarize daemon sends a POST to /v1/summarize with slidesDir set to an absolute path such as /etc/cron.d or a traversal like ../../../home/victim/.ssh, causing slide_*.png and slides.json to be written into that directory. By repeating extraction with crafted parameters, the attacker can also cause matching filenames in the target directory to be deleted, enabling tampering with application files, denial of service on collocated services, or staging follow-on attacks if the daemon runs with elevated privileges. No public exploit identified at time of analysis, but the primitive is straightforward to reproduce against any pre-0.15.1 daemon.