Vulnerability in fulgur (CVE-2026-68523)
Summary
Vulnerability in fulgur (CVE-2026-68523). Risk of unauthorized operations or information disclosure. Exploitable via fulgur. Mitigation: upgrade to 0.19.0 or later.
Original description
The description as published by the source.
fulgur converts untrusted HTML/CSS into PDF, commonly on a server that
processes input supplied by many tenants. In versions prior to 0.19.0, a
body-direct child whose CSS-resolved height greatly exceeds the page height was
sliced into one fragment per page with no upper bound.
The height is taken directly from attacker-controlled HTML/CSS (height, vh
units), so a few bytes such as `` forced on
the order of 125,000 page fragments. The pagination code then allocates
vec![Vec::new(); page_count] and runs a per-page render loop, resulting in CPU
and memory exhaustion. A non-finite height (one that resolves to +inf)
additionally made the slicing loop's remaining -= last_slice_h decrement never
terminate, causing an infinite loop.
An attacker able to submit HTML/CSS to a fulgur-based conversion service can
trigger this with a trivially small payload, denying service to the host and any
co-tenants.
Fixed in 0.19.0: a MAX_PAGES cap bounds the slice loop — halting it even for a
+inf height — and non-finite layout heights are sanitized so they can no
longer drive the loop.
Attack Vector rationale
fulgur performs no network I/O of its own; it renders HTML/CSS handed to it by
the embedding application. This advisory scores the crate independent of any
specific adopting program, so per the CVSS v3.1 User Guide §3.7 the Attack
Vector is assessed as Network for the reasonable worst-case deployment — a
network-facing service that renders untrusted HTML without user…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-68523 has been found in fulgur.
Attackers can target a specific entry point like fulgur over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade fulgur to 0.19.0 or later.
If unsure, ask your IT team or search "fulgur CVE-2026-68523" on the vendor's site.
CVE-2026-68523 (fulgur) — CWE-400 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: fulgur / height / MAX_PAGES
Patched: 0.19.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-400) exists in fulgur. Attackers reach the vulnerable code path via fulgur without authentication.
Check the vendor advisory for the affected versions of fulgur. Attack surface: fulgur / height / MAX_PAGES.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to 0.19.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'fulgur' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'fulgur' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
fulgurを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade fulgur to 0.19.0ステージング環境で 0.19.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory rustsec.org
- package crates.io
- web github.com
- web github.com
- web github.com