{ "document": { "category": "csaf_base", "csaf_version": "2.0", "distribution": { "tlp": { "label": "WHITE" } }, "lang": "en", "notes": [ { "category": "legal_disclaimer", "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings." } ], "publisher": { "category": "coordinator", "contact_details": "cert@ncsc.nl", "name": "National Cyber Security Centre", "namespace": "https://www.ncsc.nl/" }, "title": "CVE-2026-31899", "tracking": { "current_release_date": "2026-03-23T11:04:52.191740Z", "generator": { "date": "2026-02-17T15:00:00Z", "engine": { "name": "V.E.L.M.A", "version": "1.7" } }, "id": "CVE-2026-31899", "initial_release_date": "2026-03-13T19:51:05.534930Z", "revision_history": [ { "date": "2026-03-13T19:51:05.534930Z", "number": "1", "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (3).| CWES updated (1)." }, { "date": "2026-03-13T19:51:17.069477Z", "number": "2", "summary": "NCSC Score created." }, { "date": "2026-03-13T20:31:44.330513Z", "number": "3", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (2).| CWES updated (1)." }, { "date": "2026-03-13T20:31:51.503887Z", "number": "4", "summary": "NCSC Score updated." }, { "date": "2026-03-13T20:39:11.331092Z", "number": "5", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (1).| References created (2).| CWES updated (1)." }, { "date": "2026-03-13T20:39:13.375726Z", "number": "6", "summary": "NCSC Score updated." }, { "date": "2026-03-14T07:35:26.316976Z", "number": "7", "summary": "NCSC Score updated." }, { "date": "2026-03-14T12:42:58.751943Z", "number": "8", "summary": "Source created.| CVE status created. (valid)| Description created for source.| Products created (2)." }, { "date": "2026-03-14T12:43:07.778402Z", "number": "9", "summary": "NCSC Score updated." }, { "date": "2026-03-14T14:51:49.783741Z", "number": "10", "summary": "Source created.| CVE status created. (valid)| EPSS created." }, { "date": "2026-03-14T14:52:00.668645Z", "number": "11", "summary": "NCSC Score updated." }, { "date": "2026-03-16T12:27:33.286858Z", "number": "12", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (4).| CWES updated (1).| Vendor_assessment created." }, { "date": "2026-03-16T12:27:37.529613Z", "number": "13", "summary": "NCSC Score updated." }, { "date": "2026-03-16T14:39:01.641695Z", "number": "14", "summary": "Unknown change." }, { "date": "2026-03-16T14:39:03.719257Z", "number": "15", "summary": "NCSC Score updated." }, { "date": "2026-03-18T15:27:52.335387Z", "number": "16", "summary": "Products created (1).| Product Identifiers created (1).| Exploits created (1)." }, { "date": "2026-03-18T15:27:59.953782Z", "number": "17", "summary": "NCSC Score updated." }, { "date": "2026-03-19T15:28:45.417302Z", "number": "18", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (3).| CWES updated (1)." }, { "date": "2026-03-20T09:32:17.822081Z", "number": "19", "summary": "Source connected.| CVE status created. (valid)| EPSS created." } ], "status": "interim", "version": "19" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:unknown/<2.9.0", "product": { "name": "vers:unknown/<2.9.0", "product_id": "CSAFPID-5844411", "product_identification_helper": { "cpe": "cpe:2.3:a:courtbouillon:cairosvg:*:*:*:*:*:*:*:*" } } } ], "category": "product_name", "name": "CairoSVG" } ], "category": "vendor", "name": "CourtBouillon" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:unknown/<2.9.0", "product": { "name": "vers:unknown/<2.9.0", "product_id": "CSAFPID-5825963" } } ], "category": "product_name", "name": "CairoSVG" } ], "category": "vendor", "name": "Kozea" }, { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:deb/unknown", "product": { "name": "vers:deb/unknown", "product_id": "CSAFPID-5827439" } } ], "category": "product_name", "name": "cairosvg" } ], "category": "product_family", "name": "bookworm" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:deb/unknown", "product": { "name": "vers:deb/unknown", "product_id": "CSAFPID-5827440" } } ], "category": "product_name", "name": "cairosvg" } ], "category": "product_family", "name": "bullseye" } ], "category": "vendor", "name": "Debian" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-31899", "cwe": { "id": "CWE-674", "name": "Uncontrolled Recursion" }, "notes": [ { "category": "description", "text": "## Summary\n\nKozea/CairoSVG has exponential denial of service via recursive `` element amplification in `cairosvg/defs.py` (line ~335). This causes CPU exhaustion from a small input.\n\n## Vulnerable Code\n\nFile: `cairosvg/defs.py` (line ~335), function `use()`\n\nThe `use()` function recursively processes `` elements without any depth or count limits. With 5 levels of nesting and 10 references each, a 1,411-byte SVG triggers 10^5 = 100,000 render calls.\n\n## Impact\n\n- 1,411-byte SVG payload pins CPU at 100% indefinitely\n- Memory stays flat at ~43MB — no OOM kill, process never terminates\n- Any service accepting SVG input (thumbnailing, PDF generation, avatar rendering) is DoS-able\n- Amplification factor: O(10^N) rendering calls from O(N) input\n\n## Proof of Concept\n\nSave as `poc.svg` and run `timeout 10 cairosvg poc.svg -o test.png`:\n\n```xml\n\n\n \n \n \n \n \n \n \n \n\n```\n\nExpected: `timeout` kills the process after 10 seconds (it never completes on its own).\n\nAlternatively test with Python:\n```python\nimport cairosvg, signal\nsignal.alarm(5) # Kill after 5 seconds\ntry:\n cairosvg.svg2png(bytestring=open(\"poc.svg\").read())\nexcept:\n print(\"[!!!] CONFIRMED: CPU exhaustion — process did not complete in 5s\")\n```\n\n## Suggested Fix\n\nAdd recursion depth counter to `use()` function. Cap at e.g. 10 levels. Also add total element budget to prevent amplification.\n\n## References\n\n- [CWE-400](https://cwe.mitre.org/data/definitions/400.html)\n\n## Credit\n\nKai Aizen (SnailSploit) — Adversarial AI & Security Research", "title": "github - https://github.com/advisories/GHSA-f38f-5xpm-9r7c" }, { "category": "description", "text": "CairoSVG is an SVG converter based on Cairo, a 2D graphics library. Prior to Kozea/CairoSVG has exponential denial of service via recursive element amplification in cairosvg/defs.py. This causes CPU exhaustion from a small input.", "title": "nvd - https://nvd.nist.gov/vuln/detail/CVE-2026-31899" }, { "category": "description", "text": "CairoSVG is an SVG converter based on Cairo, a 2D graphics library. Prior to Kozea/CairoSVG has exponential denial of service via recursive element amplification in cairosvg/defs.py. This causes CPU exhaustion from a small input.", "title": "cveprojectv5 - https://www.cve.org/CVERecord?id=CVE-2026-31899" }, { "category": "description", "text": "CairoSVG is an SVG converter based on Cairo, a 2D graphics library. Prior to Kozea/CairoSVG has exponential denial of service via recursive element amplification in cairosvg/defs.py. This causes CPU exhaustion from a small input.", "title": "debian - https://security-tracker.debian.org/tracker/CVE-2026-31899" }, { "category": "description", "text": "A flaw was found in CairoSVG, an SVG converter. A remote attacker could exploit this vulnerability by submitting a specially crafted SVG file that contains recursive `` elements. This can lead to an exponential increase in processing time and CPU exhaustion, resulting in a Denial of Service (DoS) for the system.\nThis is an IMPORTANT denial of service vulnerability in CairoSVG, affecting systems that process untrusted SVG input. The flaw allows an attacker to trigger exponential CPU exhaustion through recursive `` element amplification. Red Hat products that include `python-cairosvg` and process untrusted SVG content are affected.", "title": "redhat - https://access.redhat.com/security/cve/CVE-2026-31899" }, { "category": "description", "text": "## Summary\n\nKozea/CairoSVG has exponential denial of service via recursive `` element amplification in `cairosvg/defs.py` (line ~335). This causes CPU exhaustion from a small input.\n\n## Vulnerable Code\n\nFile: `cairosvg/defs.py` (line ~335), function `use()`\n\nThe `use()` function recursively processes `` elements without any depth or count limits. With 5 levels of nesting and 10 references each, a 1,411-byte SVG triggers 10^5 = 100,000 render calls.\n\n## Impact\n\n- 1,411-byte SVG payload pins CPU at 100% indefinitely\n- Memory stays flat at ~43MB — no OOM kill, process never terminates\n- Any service accepting SVG input (thumbnailing, PDF generation, avatar rendering) is DoS-able\n- Amplification factor: O(10^N) rendering calls from O(N) input\n\n## Proof of Concept\n\nSave as `poc.svg` and run `timeout 10 cairosvg poc.svg -o test.png`:\n\n```xml\n\n\n \n \n \n \n \n \n \n \n\n```\n\nExpected: `timeout` kills the process after 10 seconds (it never completes on its own).\n\nAlternatively test with Python:\n```python\nimport cairosvg, signal\nsignal.alarm(5) # Kill after 5 seconds\ntry:\n cairosvg.svg2png(bytestring=open(\"poc.svg\").read())\nexcept:\n print(\"[!!!] CONFIRMED: CPU exhaustion — process did not complete in 5s\")\n```\n\n## Suggested Fix\n\nAdd recursion depth counter to `use()` function. Cap at e.g. 10 levels. Also add total element budget to prevent amplification.\n\n## References\n\n- [CWE-400](https://cwe.mitre.org/data/definitions/400.html)\n\n## Credit\n\nKai Aizen (SnailSploit) — Adversarial AI & Security Research", "title": "github - https://api.github.com/advisories/GHSA-f38f-5xpm-9r7c" }, { "category": "other", "text": "0.00055", "title": "EPSS" }, { "category": "other", "text": "4.0", "title": "NCSC Score" }, { "category": "other", "text": "There is exploit data available from source Nvd, Is related to (a version of) an uncommon product", "title": "NCSC Score top decreasing factors" }, { "category": "details", "text": "Severity: 3\n", "title": "Vendor assessment" } ], "product_status": { "known_affected": [ "CSAFPID-5825963", "CSAFPID-5827439", "CSAFPID-5827440", "CSAFPID-5844411" ] }, "references": [ { "category": "external", "summary": "Source - github", "url": "https://github.com/advisories/GHSA-f38f-5xpm-9r7c" }, { "category": "external", "summary": "Source raw - github", "url": "https://api.github.com/advisories/GHSA-f38f-5xpm-9r7c" }, { "category": "external", "summary": "Source - nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31899" }, { "category": "external", "summary": "Source raw - nvd", "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-31899" }, { "category": "external", "summary": "Source - cveprojectv5", "url": "https://www.cve.org/CVERecord?id=CVE-2026-31899" }, { "category": "external", "summary": "Source raw - cveprojectv5", "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/31xxx/CVE-2026-31899.json" }, { "category": "external", "summary": "Source - debian", "url": "https://security-tracker.debian.org/tracker/CVE-2026-31899" }, { "category": "external", "summary": "Source - first", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-31899" }, { "category": "external", "summary": "Source raw - first", "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0" }, { "category": "external", "summary": "Source - redhat", "url": "https://access.redhat.com/security/cve/CVE-2026-31899" }, { "category": "external", "summary": "Source raw - redhat", "url": "https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-31899.json" }, { "category": "external", "summary": "Source - github", "url": "https://api.github.com/advisories/GHSA-f38f-5xpm-9r7c" }, { "category": "external", "summary": "Source - first", "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0" }, { "category": "external", "summary": "Reference - cveprojectv5; github; nvd; redhat", "url": "https://github.com/Kozea/CairoSVG/security/advisories/GHSA-f38f-5xpm-9r7c" }, { "category": "external", "summary": "Reference - cveprojectv5; github; nvd; redhat", "url": "https://github.com/Kozea/CairoSVG/commit/6dde8685ed3f19837767bce7a13a5491e3d0e0bf" }, { "category": "external", "summary": "Reference - github", "url": "https://github.com/advisories/GHSA-f38f-5xpm-9r7c" }, { "category": "external", "summary": "Reference - redhat", "url": "https://www.cve.org/CVERecord?id=CVE-2026-31899" }, { "category": "external", "summary": "Reference - redhat", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31899" } ], "scores": [ { "cvss_v3": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "products": [ "CSAFPID-5825963", "CSAFPID-5827439", "CSAFPID-5827440", "CSAFPID-5844411" ] } ], "title": "CVE-2026-31899" } ] }