HispasecAugust 31, 2026🇪🇸Translated from Spanish

Over 8,300 Gitea Servers Remain Exposed to Remote Code Execution via CVE-2026-60004

Thousands of Gitea instances reachable from the internet remained unpatched at the end of August against CVE-2026-60004, a critical flaw that permits remote command execution. The fix arrived with Gitea 1.27.1, and the vulnerability has already been listed as actively exploited in the CISA KEV catalog.

The Gitea ecosystem, one of the most widely used platforms for hosting Git repositories in self-managed environments, faces a serious issue: as of August 27, 2026, 8,393 internet-exposed instances were still vulnerable to CVE-2026-60004, a critical remote code execution flaw. The situation is concerning because the vulnerability is not theoretical; active exploitation has been observed and the window for applying the patch has narrowed significantly.

The defect combines two elements that together allow an attacker to execute commands on the server. First, the diffpatch endpoint can be abused to inject content. Second, that content can lead to the installation and execution of a Git hook controlled from within the repository itself. The end result is a server running commands without the attacker needing prior operating-system access. Execution occurs without administrator privileges but with the permissions of the account running the service, typically the system user under which Gitea operates.

In many deployments this level of access is sufficient to enable data exfiltration of configuration secrets, database credentials, integration tokens, OAuth credentials, and sensitive environment variables. The actual impact depends on deployment isolation and permission models, especially when the instance runs on a shared host or with overly permissive rights.

Exploitation requires write access to a repository, yet a common weak point exists: open user registration is enabled by default in many installations. This allows an attacker to register, create a repository, and complete the attack chain without prior credentials, particularly when email confirmation is not required and anti-automation controls are absent.

The project addressed CVE-2026-60004 in Gitea 1.27.1, published on July 27, 2026. Nevertheless, the volume of unpatched instances indicates a broad attack surface, with heightened exposure for services that publish their forge directly on the internet. CISA added the flaw to the Known Exploited Vulnerabilities catalog on August 25 and set August 28 as the remediation deadline for U.S. federal agencies.

In some reported incidents, attackers used the access to deploy cryptocurrency-mining software on Docker-based installations. This pattern aligns with typical behavior against exposed services: rapid intrusion, immediate monetization, and minimal persistence. No public attribution to a specific actor or campaign has been confirmed.

Recommended actions include updating Gitea to at least version 1.27.1 and, where possible, prioritizing 1.27.2. Administrators should disable open registration if not essential or harden it with email confirmation and CAPTCHA. Indicators of compromise to review include anomalous creation or execution of Git hooks, unusual patterns on the diffpatch endpoint, sustained CPU usage, and unexpected binary downloads from the instance.

If intrusion is suspected, immediate steps include rotating all credentials and secrets, from configuration keys and database credentials to integration tokens and OAuth secrets. To reduce future exposure, network access should be restricted to necessary ranges and write permissions tightly controlled. In Docker deployments, container isolation, outbound connectivity restrictions, and network/permission hardening are advised, as command execution inside the container can escalate if the environment contains additional weaknesses.

Users of reverse-proxy authentication headers should also verify their configuration: the official Gitea Docker image is affected by a separate authentication bypass, CVE-2026-20896, when headers such as X-WEBAUTH-USER are enabled.

Related articles

Security NEXTVulnerabilities & Exploits

CISA Adds Three Actively Exploited Linux Kernel Vulnerabilities to KEV Catalog

The U.S. Cybersecurity and Infrastructure Security Agency has added three vulnerabilities affecting the Linux Kernel to its Known Exploited Vulnerabilities catalog. The flaws, identified as CVE-2025-39682, CVE-2026-53266, and CVE-2025-39964, are confirmed to be under active exploitation in the wild. CISA is directing all federal agencies to apply patches immediately and to search for indicators of compromise. The vulnerabilities impact the kernel's kTLS TLS processing, the ebtables network bridge component, and the AF_ALG cryptographic interface. Each issue can lead to memory corruption or inconsistent internal state that attackers may leverage for privilege escalation or remote code execution.

HabrVulnerabilities & Exploits

Keycloak Cluster on Three VMs: Engineers Detail Embedded Infinispan Setup, HA Testing Failures, and Bug Fix

A team deployed Keycloak for 25,000–30,000 users across a country using three isolated VMs instead of Kubernetes. They chose Embedded Infinispan with JGroups over an external cluster to reduce failure points and maintain session replication. PostgreSQL with Patroni handled shared storage and JDBC_PING discovery. Testing revealed that full datacenter outages triggered split-brain conditions and 5xx errors that the built-in healthcheck could not resolve. The engineers wrote a Python watcher script to detect multiple coordinators in the JGROUPS_PING table and restart affected containers. They reported the recovery bug to the Keycloak project, which was confirmed and fixed in a later release. The production cluster now survives single-DC loss without session loss.

HabrVulnerabilities & Exploits

From UDP Probe to Working Tunnel: Analyzing Hysteria2 Behavior via QUIC, HTTP/3 and Client Events

A detailed technical study examined how commercial Hysteria2 VPN endpoints respond to different levels of network probing, starting from simple UDP packets and progressing to full QUIC handshakes and authenticated client connections. The research used custom NetProbe tools on Windows and Linux to test real subscription endpoints, capturing both external probe results and decrypted traffic from an instrumented Hysteria2 client. Simple UDP probes received no response and timed out, while properly formed QUIC Initial packets with TLS ClientHello and ALPN h3 successfully completed handshakes using TLS 1.3 and TLS_AES_256_GCM_SHA384. An unauthenticated HTTP/3 GET request triggered immediate connection closure with H3_NO_ERROR (code 0x100), whereas a legitimate client sending POST /auth with Hysteria-Auth headers received the expected 233 status confirming authentication and UDP forwarding support. Subsequent data transfer tests, including parallel requests and file downloads, were observed inside separate QUIC streams after authentication, confirming that the tunnel carried real traffic. The study highlights differences between external probing and authenticated client behavior, providing practical insight into how Hysteria2 servers handle reconnaissance versus legitimate VPN usage.

HispasecVulnerabilities & Exploits

Unbound 1.26.1 Patches Critical DNSSEC Validator Flaw CVE-2026-81642 Enabling Remote Code Execution

NLnet Labs has released Unbound 1.26.1 to address CVE-2026-81642, a critical vulnerability in the DNSSEC validator that can cause service crashes and potential remote code execution. The flaw affects all versions up to and including 1.26.0 and is triggered when validating a malicious DNS zone. It resides in the handling of DNSKEY records, where a buffer overflow can occur during DNS response processing. The vulnerability carries a CVSS 4.0 score of 9.1 with a network attack vector, no privileges required, and no user interaction needed. Exploitation requires an attacker to control a malicious DNS zone that the resolver queries, which can lead to denial of service or RCE in the worst case. The update also includes fixes for eight additional security issues, including CVE-2026-82717 and CVE-2026-81634, both involving heap corruption.