CVE-2026-62303: Pistache is a high-performance REST toolkit written in C++
Affects pistacheSource GCVE Database
Not known to be exploited · CVSS 5.9 Medium.
Data as of 5 Nov 2026, 12:34 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 5.9 |
|---|
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 30 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSpistachepkg:deb/ubuntu/pistache?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSpistachepkg:deb/ubuntu/pistache?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
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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.
References
- ubuntu.com/security/CVE-2026-62303 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-62303 (opens in a new tab)
- github.com/pistacheio/pistache/security/advisories/GHSA-q474-pqcp-gqm5 (opens in a new tab)
- github.com/pistacheio/pistache/commit/935461352403696f3ca0dbb9a7de7d2609e7ce91 (opens in a new tab)