HOMEVULNERABILITIESCVE-2026-8503
MEDIUM

CVE-2026-8503

CWE-338Published: May 15, 2026· Updated: May 18, 2026

6.5
CVSS v3.1
EPSS:0.03%probability of exploitation in 30 daysPercentile:9.0th

Official Description

Apache::Session::Generate::SHA256 versions before 1.3.19 for Perl create insecure session ids.

Apache::Session::Generate::SHA256 generated session ids insecurely. The default session id generator returns a SHA-256 hash of the built-in rand() function, the epoch time, and the PID, that is hashed again. These are predictable, low-entropy sources. Predicable session ids could allow an attacker to gain access to systems.

Note that version 1.3.19 has a fallback without warning to use insecure session generation method if the call to Crypt::URandom::urandom fails. However, this is unlikely as Crypt::URandom is a hardcoded requirement of the module.

This issue is similar to CVE-2025-40931 for Apache::Session::Generate::MD5.

NVD Source

Technical Analysis

CVE-2026-8503 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityLow
IntegrityLow
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected Vendors & Products

guimard1 product
apache\
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/LemonLDAPNG/Apache-Session-Browseable/commit/cc915cbbd266776eec3dd8bf4748b15fa827dbd0.patch
ADVISORYhttps://www.cve.org/CVERecord?id=CVE-2025-40931
ADVISORYhttps://www.cve.org/CVERecord?id=CVE-2025-40932

All References (5)

→
https://github.com/LemonLDAPNG/Apache-Session-Browseable/commit/cc915cbbd266776eec3dd8bf4748b15fa827dbd0.patchPatch
→
https://metacpan.org/release/GUIMARD/Apache-Session-Browseable-1.3.19/changesRelease Notes
→
https://metacpan.org/release/GUIMARD/Apache-Session-Browseable-1.3.19/diff/GUIMARD/Apache-Session-Browseable-1.3.18#lib/Apache/Session/Generate/SHA256.pmProduct
→
https://www.cve.org/CVERecord?id=CVE-2025-40931Third Party Advisory
→
https://www.cve.org/CVERecord?id=CVE-2025-40932Third Party Advisory

Quick Facts

CVE IDCVE-2026-8503
CVSS Score6.5 / 10
SeverityMEDIUM
WeaknessCWE-338
CISA KEVNo
EPSS (30d)0.03%
Affected1 vendor
PublishedMay 15, 2026

Related CVEs (CWE-338)

CVE-2026-2439
9.8
CVE-2025-15578
9.8
CVE-2025-15604
9.8
CVE-2025-40926
9.8
CVE-2026-3256
9.8
CVE-2026-11832
9.1

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-8503 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
← All Vulnerabilities·Search for CVE-2026-8503·NVD
CVE-2026-8503 — CVSS 6.5 MEDIUM | CTIWATCH.COM