← Back to CVE Explorer

CVE-2026-62303

Full vulnerability record from the local CVENow database.

Description

Pistache is a high-performance REST toolkit written in C++. From 0.0.5 through 0.4.26, `SegmentTreeNode::sanitizeResource()` in `src/server/router.cc` uses `std::regex_replace()` with the `//+` expression to collapse consecutive slashes. With libstdc++, a path containing tens of thousands of consecutive slash characters can recurse deeply enough to exhaust the stack and crash the process. `Router::route()`, `Router::addRoute()` and `Router::removeRoute()` reach this normalization. Unauthenticated remote exploitation is conditional on a deployment allowing sufficiently long request paths, such as by increasing `Endpoint::Options::maxRequestSize()` above the default 4096-byte limit or forwarding long paths through a front end. Direct router API use is also affected when attacker-controlled route or resource strings reach the normalizer. Native builds reproduced a crash around 24,000 consecutive slashes, although the exact threshold depends on the stack and standard library; the demonstrated failure is stack exhaustion rather than uninitialized-memory use. A source fix replaces recursive regular-expression normalization with an iterative pass, but no containing repository release was verified as of time of publication.

Severity
MEDIUM
CVSS score
5.9 (v3.1)
Vulnerability status
Deferred
Source identifier
Published
2026-10-30 19:18:33.217000
Last modified
2026-10-30 19:39:14.897000
View original CVE JSON
{
  "id": "CVE-2026-62303",
  "sourceIdentifier": "[email protected]",
  "published": "2026-10-30T19:18:33.217",
  "lastModified": "2026-10-30T19:39:14.897",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Pistache is a high-performance REST toolkit written in C++. From 0.0.5 through 0.4.26, `SegmentTreeNode::sanitizeResource()` in `src/server/router.cc` uses `std::regex_replace()` with the `//+` expression to collapse consecutive slashes. With libstdc++, a path containing tens of thousands of consecutive slash characters can recurse deeply enough to exhaust the stack and crash the process. `Router::route()`, `Router::addRoute()` and `Router::removeRoute()` reach this normalization. Unauthenticated remote exploitation is conditional on a deployment allowing sufficiently long request paths, such as by increasing `Endpoint::Options::maxRequestSize()` above the default 4096-byte limit or forwarding long paths through a front end. Direct router API use is also affected when attacker-controlled route or resource strings reach the normalizer. Native builds reproduced a crash around 24,000 consecutive slashes, although the exact threshold depends on the stack and standard library; the demonstrated failure is stack exhaustion rather than uninitialized-memory use. A source fix replaces recursive regular-expression normalization with an iterative pass, but no containing repository release was verified as of time of publication."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "pistacheio",
          "product": "pistache",
          "versions": [
            {
              "version": ">= 0.0.5, <= 0.4.26",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 5.9,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 3.6
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-400"
        },
        {
          "lang": "en",
          "value": "CWE-674"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/pistacheio/pistache/commit/935461352403696f3ca0dbb9a7de7d2609e7ce91",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/pistacheio/pistache/security/advisories/GHSA-q474-pqcp-gqm5",
      "source": "[email protected]"
    }
  ]
}